From traditional medicine to personalized medicine

From prehistory, where medicine started began with plants, minerals and parts of animals; until today, medicine has evolved very quickly. Much of the “fault” of his fact is due to genetics, which allows us to talk about personalized medicine. In the following article we discuss this.

THE EVOLUTION OF DISEASES

To talk about medicine, we have first to know diseases. We cannot think that all diseases are genetic, but there are diseases related to anatomical changes, fruit of our evolution.

Chimpanzees are the closest animal to us, humans, with which we share 99% of our genome. Despite this, humans have very particular phenotypic characteristics as the brain most develop, both in size and expansion of the cerebral cortex; hairless sweaty skin, bipedal posture and prolonged dependence on offspring, allowing the transmission of knowledge for longer; among other.

Possibly, the bipedal position was key to the early development of the divergence between the chimpanzee lineage and that of humans; and is also the reason for the appearance of some diseases related to anatomical factors. Among them are hernias, haemorrhoids, varices, disorders of the spine, such as herniated intervertebral discs; osteoarthritis in the knee joint, uterine prolapse and difficulties in childbirth.

The fact that the pelvis was remodelled (Figure 1) and narrower resulted in obstetric problems millions of years later, when the brain expanded. Consequently, the skull as well. The heads of the foetuses were longer and larger, making birth difficult. This explains why the deliveries of humans are longer and longer compared to those of chimpanzees and other animals.

Figure 1. Comparison between human pelvis and chimpanzee pelvis in bipedal position (Source: Libros maravillosos – La especie elegida (capítulo 5))

The evolution towards modern life has behaved many changes in every way. In comparison to our hunter-gatherer ancestors (Figure 2), our diet has changed a lot and has nothing to do with what other primates eat. For the latter, the fruit represents most of the intake, but for us it is red meat. In addition, we are the only animals that continue to feed us milk after the lactation period.

Figure 2. Picture of hunter-gatherer humans (Source: Río Verde en la historia

If we add to the sedentary lifestyle and the limited physical activity of modern humans, it can help explain the seriousness and frequency of some modern human diseases.

Lifestyle can also affect us. For example, myopia, which rate is higher in western individuals who read a lot or do activities of near vision, compared to individuals of Aboriginal’s towns.

Another clear example is the alteration in the female reproductive stage. Currently, women have children more and more later. This is also linked to a decrease in the duration of breastfeeding. These changes, which can be considered socially positive, have negative effects on the health of the reproductive organs. It has been shown that the combination of early menarche, limited or no breastfeeding and later menopause are the main risk factors for breast and ovarian cancer.

Humans increasingly live more years and we want the best quality of life. It is easy for more longevity to appear more diseases, by the deterioration of the organism and its cells.

THE EVOLUTION OF MEDICINE

The history of medicine is the history of the struggle of men against disease and since the beginning of this century, is also the history of human effort to maintain health.

We have acquired the scientific knowledge of medicine based on observation and experience, but it has not always been so. Our ancestors experienced sickness and the fear of death before a rational picture could be made of them, and the medicine of that time was immersed in a system of beliefs, myths and rites.

However, in the last years it has been born personalized genomics, which tells you your risk factors. This opens a door to personalized medicine, which adjusts treatments to patients depending on their genome (Figure 3). It uses information from a person’s genes and proteins to prevent, diagnose and treat a disease, all thanks to the sequencing of the human genome.

Figure 3. Personalized medicine that treats people individually, according to their genome (Source: Indiana Institute of Personalized Medicine)

Molecular methods that make precision medicine possible include tests of gene variation, proteins, and new treatments targeting molecular mechanisms. With the results of these tests and treatments can determine the state of the disease, predict the future state of the disease, the response to the drug and treatment or even the role of the food we eat at certain times, which results of great help to the doctors to individualize the treatment of each patient.

To do this, we have within our reach the nutrigenetics and the nutrigenomics, that like the pharmacogenetics and the pharmacogenomics, they help the advance of a medicine is more and more directed. Therefore, these disciplines are today one of the pillars of personalized medicine since it involves treating each patient individually and tailor-made.

The evolution towards precision medicine is personalized, preventive, predictive and participatory. There is increasing access to information and the patient is more proactive, getting ahead of problems, preventing them or being prepared to deal with them efficiently.

REFERENCES

• Varki, A. Nothing in medicine makes sense, except in the light of evolution. J Mol Med (2012) 90:481–494
• Nesse, R. and Williams, C. Evolution and the origins of disease. Sci Am. (1998) 279(5):86-93
• Mackenbach, J. The origins of human disease: a short story on “where diseases come from”. J Epidemiol Community Health. (2006) 60(1): 81–86
• Main picture: Todos Somos Uno

Check the evolution in your own body

42% of the US population and 11.5% of the Spanish people do not believe in evolution. However, there are different evidence that Darwin was right, some of them in your own body. Have you had your appendix or wisdom teeth removed? Find out in this post which vestigial organs you have inherited from your ancestors.

WHAT ARE VESTIGIAL STRUCTURES?

Vestigial structures (often called organs althouth they are not organs properly) are body parts that have been reduced or have lost its original function during the evolution of a species. They can be found in many animals, including humans.

Orca skeleton in which vestiges of the hind limbs can be seen. This is a proof of its terrestrial origins. Photo: Patrick Gries

Vestigial structures were fully functional in the ancestors of these species (and in the homologous structures of other existing species), but currently its function is practically useless or it has changed. For example, the second pair of flying wings in some insects such as flies have lost their function and they have been reduced to balance organs (halteres). If you want to know more about the evolution of flight in insects click here.

Besides physical structures, vestigial features can also manifest itself in behavior or biochemistry processes.

WHY ARE THEY  EVIDENCE OF EVOLUTION?

Natural selection acts on species favoring features that increase their survival and eliminating the ones with no benefits, for example when changes appear in the habitat. Individuals with unfavorable characteristics will die or will breed less and that feature will be removed after some generations, while favorable traits will remain as their carriers can pass them to the next generation.

Sometimes there are features that are neither favorable nor unfavorable, so they continue appearing in the next generations. But all has a cost structure (energy, risk to become infected, develop tumors…), so selective pressure continues acting to eliminate something that is not conducive to the success of the species. This is the case of vestigial structures, which “take longer” disappear throughout evolution. Their existence reveal that in the past these structures had an important role in our ancestors.

FIND YOUR VESTIGIAL TRAITS

THE NICTITATING MEMBRANE

We talked about it in How animals see the world. The third eyelid is a transparent or translucent membrane that protects and moisten the eye without losing visibility. It is common in amphibians, reptiles and birds. Among primates, it is only functional in lemurs and lorises.

Nictitating membrane or third eyelid of a masked lapwing (Vanellus miles). Photo: Toby Hudson

In humans the plica semilunaris is a remnant of the nictitating membrane. Obviously we can not move it but still has some lacrimal drainage function and helps on the eye movement (Dartt, 2006).

Plica semilunaris. Photo: unknown

DARWIN’S TUBERCLE AND EAR MUSCLES

10% of the population has a thickening in the ear, a vestige of the common pointy ear in primates. This structure is called Darwin’s tubercle and has no function.

Variability of Darwin’s tubercle at the top of the ear (0 = absent).  Credit.

Comparison between the ear of a yellow baboon (Papio cynocephalus) and ours. Credit

Also, primates (and other mammals) have mobile ears to lead the pinna toward the sound source: surely you have noticed it in your house dog or house cat. Humans (and chimps) no longer have that great mobility, although some people may move slightly pinna. It has been proven with electrodes these muscles are excited when we perceive a sound that comes from a particular direction (2002).

Auricular muscles responsible of movement of the pinna. Credit

The occipitofrontalis muscle has lost its function to prevent the head from falling, but participates in facial expression.

PALMARIS LONGUS MUSCLE

16% of Caucasians do not have this muscle on the wrist, neither 31% of nigerian people neither 4,6% of chinese people. It can even appear in one arm and not in the other or be double.

It is believed that this muscle actively participated in the arboreal locomotion of our ancestors, but currently has no function, because it does not provide more grip strength. This muscle is longer in completely arboreal primates (like lemurs) and shorter in land primates, like gorillas (reference).

And do you have it or not? Try it: join your thumb and pinky and raise your hand slightly.

I have two palmaris longus in the left arm and one on the right. Photo: Mireia Querol

WISDOM TEETH

35% of people do not have wisdom teeth or third molar. In the rest, its appearance is usually painful and removal is necessary.

I don’t have the third molar. Photo: Mireia Querol Rovira

Our hominin ancestors had them, much bigger than ours. A recent research explains that when a tooth develops, emits signals that determine the size of the neighboring teeth. Reducing the mandible dentition and the other along evolution has resulted in reduced molars (and eventually the disappearance of the third).

Comparison between the dentition of a chimpanzee, Australopithecus afarensis and Homo sapiens. Look at the reduction of the last three molars between afarensis and sapiens, Credit

THE TAILBONE

If you touch your spine till the end, you will reach the coccyx or tailbone. It is three to five fused vertebrae, vestige of the tail of our primate ancestors. In fact, when we were in the womb, in the early stages of embryo development a 10-12 tail vertebrae formation is observed.

Different stages in human embryonic development (1 to 8) and comparison with other species. Credits in the image.

Subsequently it is reabsorbed, but not in all cases: it has been reported 40 newborns with a tail.

Infant born with tail. A mutation has prevented the growth inhibition of the tail during pregnancy. Credit

Although we have no tail, currently these bones serve as anchors of some pelvic muscles.

Tailbone position. Photo: Mireia Querol Rovira

SUPERNUMERARY NIPPLES (POLYTHELIA)

It is estimated that up to 5% of the world population has more than two nipples. These “extra” nipples can be presented in different ways so sometimes are confused with freckles or moles. They are located in the mammillary line (from the axilla to the groin), exactly in the same position as other mammals with more than two breasts (observe your house dog, for example). Usually the number of breasts corresponds to the average of offspring that has a mammal, so extra nipples would be a vestige from when our ancestors had more offspring per birth. Usual is 3 nipples, but has been documented a case of up to 8 nipples in a person.

Additional nipple below the main one. Credit

FIND YOUR VESTIGIAL REFLEXES AND BEHAVIOURS

PALMAR AND FOOT SOLE GRASP REFLEX

Surely you’ve experienced that if you bring anything into the hands of a baby, automatically he grabs it with such a force that would be able to hold his own weight. This reflex disappears at 3-4 months of age and is a remnant of our arboreal past and the way to grab the hair of the mother, as with the other current primates. Watch the next video in 1934 on a study of twins (minute 0:34):

On the feet there is also a reflex of trying to grab something when the foot of a baby is touched. It disappears at 9 months of age.

By the way, have you noticed how easily children climb on any handrails or higher zones in a playground?

GOOSEBUMPS

Cold, stress or intense emotion (eg, listening to some music) causes the piloerector muscle to raise the hair giving the skin the appearance of a plucked chicken. It is an involuntary reflex in which some hormones, like adrenaline (which is released in the mentioned situations) are involved. What utility had this to our ancestors and has in modern mammals?

• Increasing the space between the skin and the external surface, so that hot air trapped between hair helps on maintaining temperature.
• Looking bigger to scare off potential predators or competitors.

Chimpanzee with hair bristling in a display before a conflict. Photo: Chimpanzee Sanctuary Northwest

Obviously we have lost hair in most parts of the body, so although we retain the reflex, it has no use to us or to keep warm or to ward off predators. The hair has been preserved abundantly in areas where protection is necessary or due to sexual selection (head, eyebrows, eyelashes, beard, pubis…), but in general, can also be considered a vestigial structure.

There are more vestigial structures but in this post we have focused on the most observable. In future posts we will discuss other internal structures, like the famous appendix or vomeronasal organ.

REFERENCES

• Proof of evolution that you can find on your own body
• 10 Vestigial Traits You Didn’t Know You Had
• Darwin was right
• Los reflejos de prensión palmar y plantar
• Resuelto el enigma de las muelas del juicio
• Politelia bilateral familiar

Eating meat made us human

Currently some of the world’s population can choose their diet: omnivorous, vegetarian, vegan, raw foodism, carnivorous, paleodiet… but what ate our ancestors?  Which diet is more suited to the one of our ancestors? Without going into polemics, we will discuss one of the crucial facts of the evolution from Australopitechus to Homo: the meat intake.

WHAT DID OUR RELATIVES EAT ?

One of the reasons given to follow a strict vegetarian or vegan diet is that as “we are apes”, they feed on fruits and plants, and moreover, a more “natural” diet  is achieved. Currently and traditionally the base of the world diet are the seeds of cereals (rice, wheat, corn, etc.) and legumes (beans, lentils…), which often require processing (flour, for example) and have nothing to do with their wild ancestors. Since agriculture and livestock was invented and we have selected the best varieties for human consumption, the label “natural” loses all meaning. Although transgenic food is now on everyone’s lips, we have been using the genetic modification for thousands of years.

In the top row, wild ancestors of lettuce, carrot and corn. Below, domestic varieties. Source

That we are apes and the natural thing is to eat vegetables, is also not entirely true. As primates have evolved in trees, hominids have a strict diet or mainly folivorous -leaves- and frugivorous -fruit- (gorillas, orangutans), while gibbons also complete their diet with invertebrates. Our closest relatives however (bonobos, chimpanzees) are omnivorous as they eat vegetables, fruits, invertebrates and even small mammals and other primates (althought in less proportion than vegetables).

Chimpanzee eating meat. Populations of chimpanzees have been described  hunting with spears made by themselves. Photo Cristina M.Gomes, Max Planck Institute.

No wonder then that our direct distant ancestors as Australopithecus Lucy, ate leaves, fruits, roots and tubers as the basis of their diet. Some species, in addition to vegetables, also fed on invertebrates and small vertebrates, similar to modern chimpanzees.

HERBIVOROUS AND CARNIVOROUS

Fruits have more sugars, although they are not very abundant in comparison with leaves and stems. But leaves have less nutritional value because they contain many fibers we can not absorb, such as cellulose. Legumes contain more protein than grains, but some essential amino acids and vitamins (such as B12) are absent or in a few proportion in vegetables and easily assimilable iron (hemo iron) is found only in food with animal origin.

In short, vegetables are harder to digest compared to animals, so mammalian herbivores have longer digestive systems, or compartmented stomachs, chew over long periods of time and some are ruminants, while carnivores have digestive systems with lower absorption surface and require little chewing of food.

Digestive systems of non-ruminant herbivores, ruminants, insectivores and carnivores. Unknown author

 

WHY OUR ANCESTORS STARTED EATING MORE MEAT?

2.6 million years ago, climate change made our planet cooler and drier. In Africa the savanna dominated much of the territory, so hominids had to deal with hard leaves, leaves covered with wax, hard or thorny stems, roots… these difficult to digest resources were utilised by Paranthropus, with large teeth and powerful musculature in the jaw to crush, although they had a similar brain to Australopithecus. They became extinct a million years ago.

Paranthropus boisei. Reconstruction by John Gurche, photo by Chip Clark.

But another group of hominins found a kind of resources that offered them more energy in smaller quantities, and were easier to chew: meat. Homo habilis was the first to eat meat at higher rates than the rest of relatives and also meats with more fat. It was an opportunist: they ate almost anything edible, instead, Paranthropus were specialists, so if their food was scarce, they had more possibilities to die.

BIG BRAINS …

While Australopithecus and Paranthropus had a cranial capacity of 400-500 cm ³, Homo habilis had up to 700 cm ³. This increased brain size allowed them greater versatility and ability to improvise to find food.

One thing that clearly differentiates us from other primates and animals is the large size of our brain. As you have noticed, H. habilis and is classified within our genus,  Homo, due to that great leap of brain size, among other things.

Skull comparison between Australopithecus, Homo habilis and Paranthropus. Credit: Peter S. Ungar et al, 2011.

But a large brain also has drawbacks: 25% of our body’s energy is consumed by the brain at rest, H. habilis brain consumed 15% and Australopithecus only 10%. In addition to quantity, this energy also has to have quality: some fatty acids for proper brain function only are found in some nuts, but especially in animal fat, easier to achieve if vegetables were scarce.

Homo habilis reconstruction by Elisabeth Daynès, Cosmocaixa (Barcelona). Photo by Mireia Querol

…SMALL INTESTINES …

The only way to dedicate more energy to brain function is to reduce the size of other high energy consumer organs (Aiello, L. Wheeler, P, 1995). Heart, kidney, liver, they are major consumers of energy, but vital, so the solution is to reduce the gut and that’s only possible with the change of an almost exclusively vegetarian diet (Australopithecus) to another of easier assimilation with more protein and animal fat (H. habilis).

Comparison between high energy consumer organs between humans and other primates. Image by J. Rodriguez

…AND TOOLS

A large brain also gave another advantage to H. habilis. Despite his appereance (small, no large fangs or claws) they could make use of a great variety of meat (first as scavengers and later as hunters) due to the use of tools. Australopithecus probably used some sort of simple tools, mostly wooden made, but we know for sure that early manufacture of stone tools (archaeological industry) belong to H. habilis. This allowed them to take advantage of the inside of the bone marrow of large prey killed by carnivores when all the flesh had been eaten by other animals. Currently only hyenas and bearded vultures can access this resource without tools. Besides, by not requiring such large teeth and jaws, the skull can accommodate a larger brain.

H. habilis scavenging a rhino. Source; DK FindOut

CONCLUSION

In short, the increase of the brain of Homo was possible by changing diet, which allowed a shorter digestive tract and smaller masticatory apparatus. In turn, to achieve these more energy foods more intelligence is required, resulting in more complex behaviors such as the use of manufactured tools (Oldowan lithic technology, Mode 1).

Our digestive system is the result of millions of years of evolution as opportunistic omnivores. Some current strict diets (vegetarian or almost carnivorous) are in contradiction with this biological heritage and the abuse and access to all kinds of food carry us all kinds of allergies and food problems. The secret remains following a balanced and varied diet.

REFERENCES

• Roberts A (2002).  Evolución: historia de la humanidad. Akal, UK.
• Mateos A, Rodríguez J (2010). La dieta que nos hizo humanos. CENIEH, Burgos.
• Arsuaga J L, Martínez I (2006). La especie elegida. La larga marcha de la evolución humana. Booket divulgación.
• Potts, Richard. Sloan, Christopher (2010). What does it mean to be Human? Ed. National Geographic Society.
• Vegetarianismo – Aspectos nutricionales a tener en cuenta cuando te planteas ser vegetariano
• Paleodieta: hábitos prehistóricos para otra dieta milagro (OCU)

Koko, the gorilla who can talk with her hands

The origin of language is one of the unknowns that creates more discussion among anthropologists. Are we the only animals with a language with grammar? Did our ancestors speak? Do animals communicate only by imitating simple sounds? This article will attempt to address these issues and introduce Koko, the gorilla who learned sign language.

CAN ANIMALS SPEAK ?

Clearly most living beings communicate in some way, either through visual, olfactory or chemical, acoustic signals… The clearest case we have close is barking, meowing… but also plants can communicate.

You have probably ever heard a parrot or parakeet say words, even the crows are great imitators. But it is just that, an imitation of few words. They are unable to make sentences or use the words they know to express new concepts. Or have a conversation. Sometimes scientists have educated baby apes as humans, in an attempt to teach them to speak. They never made it.

WHAT IS NECESSARY TO SPEAK ?

Given the depth of the subject, we can summarize that to talk is essential to have the necessary cognitive capabilities and a physical vocal apparatus that enables control of entry and exit of air in a certain way . Since some animals like whales, birds or apes have high cognitive abilities, why they do not start talking the same way as us? We begin to understand their way of communicating, so it is possible that some possess some sort of grammar, or a language such as dolphins or some birds. Or maybe we should clarify what is language. In this post we will focus on the case of primates, especially gorillas and chimpanzees.

VOCAL APPARATUS

The larynx contains the vocal cords. Notice the difference between a human and a chimpanzee:

Vocal apparatus of a chimpanzee and a human. Unknown author. Photo taken from UOC

Humans have the vocal cords in a lower postion, and we have a shortest oral and nasal cavity. To produce vocals clearly, the oral communication core, the larynx must be in a low position. That is why chimpanzees, cannot talk due to their physical limitations.

 

Model with the different positions of the vocal apparatus necessary to pronounce vocals. Photo by Mireia Querol, CosmoCaixa, Barcelona.

To investigate whether our ancestors could talk, studies focus mainly on the morphology of the hyoid bone, the position of the pharynx, the base of the skull and the brain impressions inside the skull. Recent research with Skull 5 of the Sima de los Huesos belonging to a Neanderthal, along with other studies of other fossils, suggests that 500,000 years ago they had a vocal apparatus like ours. If Neanderthals had the physical conditions did they speak?

BRAIN CAPACITY

Humans are the mammals with the largest brains relative to our bodies. The intelligence of a chimpanzee is compared to 4 years old child. If they can not speak for physical limitations, could they do it otherwise?

Brain pointing out Broca’s and Wernicke’s areas, responsible for language. Homo habilis and possessed. Photo of public domain taken from NIH

According to a study published in Nature , the FOXP2 gene appears to be responsible for our ability to control of precises movement that allows speech. People with inactive copies of this gene, have severe speech and language problems. The FOXP2 gene is different in only two amino acids between chimps and humans, and apparently is responsible that neither they nor the rest of vertebrates can talk. This difference, this mutation is believed to have appeared 500,000 years ago. Svante Pääbo and his team discovered that this gene was already like ours in Neanderthals. If this is true, added to what we have seen in the previous section, we can almost ensure that Neanderthals could speak.

TEACHING TO TALK TO OTHER APES

Since they can not talk, scientists have taught apes to communicate with humans by lexigrams (drawings respresentan words) and sign language. Washoe was the first non-human ape to learn the American Sign Language (ASL). It was a chimpanzee, learned about 350 words and taught his son some Loulis. Other chimpanzees were capable of it, but the most fascinating is the discovery of this communication behavior of wild chimpanzees signs (obviously, chimpanzees own signs, not the ASL). The bonobo Kanzhi communicated with lexigrams, and Koko has become a famous gorilla thanks to her mastery of ASL.

KOKO THE GORILLA

Koko (short for Hanabiko,  in Japanese, “Fireworks”) is a western lowland gorilla. Gorillas are the largest apes and hominids nowadays, with up to 180 Kg weight in males.

Koko in 2010. Photo by Ron Cohn, Koko.org.

 

After chimpanzees and bonobos, gorillas are the most genetically similar to humans (we share more than 98% DNA). There are two species of gorillas:

• Western Gorilla (Gorilla gorilla) includes two subspecies, the western lowland gorilla (Gorilla gorilla gorilla) and the Cross River gorilla (Gorilla gorilla diehli). It is critically endangered according to IUCN .
  
• Eastern Gorilla (Gorilla beringei): includes the mountain gorilla (Gorilla beringei beringei) and the eastern lowland gorilla (Gorilla beringei graueri). It is endangered according to IUCN .

Distribution of great apes. Map shared from Great Apes Survival Partnership

 

KOKO’S LEARNING

Koko was born in 1971 in the San Francisco Zoo, and currently lives in the Gorilla Foundation in Redwood City, California. Since she was 6 months old Dr. Francine (Penny) Patterson (then PhD student) and Dr. Ron Cohn taught her American Sign Language (ASL). Other gorillas that were attached to the project were Michael (in 1976) and Ndume (1991).

Penny teaching Koko (right) and Michael ASL. Photo taken from Koko.org

Since then, Koko has learned up to 1000 ASL signs and understands approximately 2,000 words in English. It is even capable of combining different signs to explain concepts if seh don’t know the word. Michael and Ndume also managed to communicate through signs: Ndume learned some from Koko, which could prove Koko’s case is not unique but gestural communication is intrinsic in gorillas.

In this video Penny asks what Koko would like to do with their spare time. She answers that she would like to have a baby and thanks Penny when she tells her that they are trying:

OTHER SKILLS OF KOKO

Koko, living in a humanized environment, performs acts by imitation, according to researchers, she has not been forced to do so. She look at books, movies, makes paintings, looks her in the mirror, take care of pets… even plays the flute. This is especially important because it is capable of puckering in the proper position and control breathing. It can also simulate cough, which requires control over the larynx. Contrary to what was thought, control over the airways and therefore on future capabilities of our ancestors speaking, could have appeared millions sooner than previously thought.

Koko video playing flutes and harmonica (Koko.org):

Another subject worthy of study is the artistic ability of Koko and Michael. If other apes have created tools and language, it is art what separates us from them and our ancestors? Since Koko can communicate with a common language to us and puts names to her creations, is this some symbolic capacity? The line between apes and other H. sapiens, and therefore also between H. sapiens and other Homo, is getting thinner.

Kokopainting a picture. Photo from Koko.org

 

PROJECT KOKO MILESTONES

Finally, we leave you with the most important milestones after 40 years of study with Koko:

• Gorillas can learn ASL (1,000 signs) ant do it faster during childhood, and know how to modulate these signs to give them different emphasis
• They understand spoken English (2000 words)
• Koko is not a unique case, as Michael and Ndume testify
• Inventive: they can expand language combining signs learned with other signs (eg, “bracelet finger” to express “ring”), or by adding own gestures .
• Emotions: they express a variety of emotions, from the simplest to the most complex. It is known Koko reaction after the death of one of its kittens, Robin Williams, or a sad scene in film.
• Hypothesis of empathy: the gorillas may have empathy, looking at how she treats persons or animals .
• Use of grammatical language
• Other ways to communicate: including creation of drawings, photographs, pointing to words, letters with phrases …
• Self-identity: Koko is defined in front of a mirror as “fine animal / person gorilla”. Watch the video:

REFERENCES

• Human development (2002). Delval, J. XXI Century Editors Spain
  
• Koko.org . The Gorilla Foundation
• Sobre els Orígens the llenguatge (UOC)
• Instituto Max Planck. Hace medio millón de años una mutación nos ayudó a hablar y aprender
• Los monos ya saben hablar
• La ampliación del espacio cognitivo en el eje filogenético
• Áreas Broca’s and Wernicke (EduCaixa)
• Los simios y sus increíbles capacidades
• Gorillas (Great Apes Survival Partnership)
• Cover image: frame of the documentary “Koko, A -1978 talking gorilla.” Photo taken from mubi .

Reasons to have captive primates (or maybe not!)

These days there is a lot of controversy in Spain because of the TV program “Vaya Fauna” in Telecinco, in which captive non-domestic animals show their abilities. Leaving aside the training methods that suffer these animals, like in a previous post by Marc Arenas, Reasons to watch marine mammals in captivity (or maybe not), in this post we will talk about the consequences of keeping primates in captivity, especially great apes, and what is in your hands to preserve your closest relatives, all of them endangered.

MONKEYS SEEM HAPPY INTERACTING WITH US

Surely you’ve ever been to the zoo and have observed human behavior mockery to chimpanzees, gorillas and orangutans. People laughing, pounding his chest, imitating vocalizations. They are responded by chimpanzees, so we believe is an imitation game.

Humans have a tendency to humanize everything, that is, to perceive the reactions of others as human beings, which is not usually related. In the primate communication, the look is very powerful, sometimes intimidating. Who does not look the other way in the elevator when we are with a neighbor? This also happens with gorillas: staring look into their eyes is to them an aggression, so you can suppose the stress of feeling threatened by hundreds of visitors at a zoo watching at you every day. What we interpret as a smile, in which the animal bares his teeth, is actually a gesture of fear or tension. What we interpret as a game or insult, like throwing feces against the glass, it is also a sign of discomfort and stress.

This chimpanzee is not laughing, he’s scared. Photo: Photos.com

The typical gesture of striking the breast, it is actually a demonstration of strength and health, which can lead to tense situations such as that experienced by this family at the zoo in Omaha when her daughter beat his chest in front of a silverback (male gorilla):

IN ZOOS THE FACILITIES ARE MORE NATURALIZED NOWADAYS

It is true that the trend in zoos is increasingly to mimic the conditions that they could have in nature, with green spaces, logs or ropes to climb, according to species. But primates enjoy these conditions a few hours a day, specifically when zoos are open to the public. At night or in adverse weather conditions, many zoo animals live in cages smaller than the display area without any natural setting.

Most great apes are social and have well-established group hierarchies in nature. In captivity, family groups tend to be artificial because the animals are from different origins, in addition to cases where there is overcrowding (too animals in the same facility) or they are kept isolated in cages with tiny dimensions. In case of conflict within a group, animals do not have enough space to keep their distance and avoid future tensions.

Foraging gorillas in the Volcanoes National Park, Rwanda. Picture by Philip Kromer.

They are also deprived of natural behaviors such as foraging. In the case of lowland gorillas (Gorilla gorilla gorilla), they can travel several kilometers a day searching for food (mainly shoots, but also fruit and some insects) and never sleep two consecutive nights in the same place. Enrichment plans in zoo are essential to occupy their free time available.

Inappropriate behavior of some visitors does the rest (hitting glass, shouts, pictures with flash, food, excessive influx of public …).

IT HAS EDUCATIONAL AND CONSERVATIONAL VALUE

As in the case of marine mammals, investigations in captive primates do not allow reliable conclusions about the biology and behavior of animals due to the artificial conditions in which they live. In zoos, primates are not animals used in performances or in educational visits to the general public, in other centers, the information given about them is poor and biased in favor of the show or simple display of the animal to the public. The reintroduction of primates in the wild is very complex. The captive breeding programs that are implemented increasingly in zoos for conservation reasons, often produce animals for exhibition and not to release into the natural environment, for lack of means or interest.

THEY ARE ADORABLE AS PETS

The fact that an animal may seem to us nice-looking or share more than 90% of genes with us, does not mean that it will have same needs. These needs usually are not known by people who acquire a primate as a pet, causing them health problems both physical and psychological, including death.

Most come from illegal trade, which means that to capture a baby, hunters have to kill several members of its family, especially in the case of great apes that will protect their offspring to death.

The most famous orphan primate was undoubtedly Snowflake, the only albino gorilla known to date. In this case, his entire family was murdered in 1966 by entering banana and coffee plantations in the jungle of Nko, Equatorial Guinea. Snowflake was sold to Jordi Sabater Pi by 15,000 pesetas in Barcelona and was raised in an apartment in the first 11 months. Then was moved to Barcelona Zoo where he became a symbol of the city and lived there the rest of his life.

Snowflake on an inside installation. Photo taken from blog Sigur Rós.

Small primates are also victims of illegal trade, which has increased because of the presence of videos on the Internet about how “adorable” are marmosets or loris (Nycticebus) according to a study published in PLoS ONE. Besides many species are endangered, as we saw in a previous post slow lorises are the only poisonous primate in the world, so they are mutilated without anesthesia (they cut them teeth, claws…) before sale, which provoke sometimes deadly infections. The study found only in Indonesia 15,000 loris enter the illegal market per year, not counting those who die before. To that evidence must be added the death of the mother and/or entire families. They are sold with a few months of life, when in the wild spend the first 14 months with its mother, so their emotional and nutritional needs will never be covered.

Loris from Sumatra to sell crammed in a cage without food or water, in daylight (they are nocturnal). Photo by The Little Fireface Project.

It is estimated that the illegal trade in wildlife is worth more than 19 billion dollars annually, equivalent or above the illegal trade in drugs and weapons. In addition to pets, many primates living in zoos come from seizures, like Coco gorilla at Barcelona Zoo.

The Primates order is protected by CITES (Convention on International Trade in Endangered Species of Wild Fauna and Flora), so trade is banned or highly regulated. In Spain for example, they can’t be kept in particular installations.

THEY ARE VERY SMART AND CAN DO THINGS LIKE US

Another clear case of humanization is forcing primates to represent situations taking them as natural and easy to learn for them,  like walking upright, cycling and other stunts that are fortunately seen less and less in circuses, movies, commercials or sets of TV.

We have already discussed the origin and living conditions (often unhealthy) of these animals. We won’t go into detail about how they are trained, based on negative reinforcement (deprivation of food, company, beatings, imprisonment…) or stress levels to which they are subjected between spotlights, people and noise. Primatologist Sarah Baeckler conducted a study in 2002 on the status and conditions of these animals. What happens to them when they do not serve to act? They are abandoned, and in lucky cases recovered in sanctuaries or recovery centers, such as Mona Foundation in Catalunya or the Tchimpounga Chimpanzee Rehabilitation Center, the largest sanctuary for chimpanzees in Africa promoted by Dr. Jane Goodall. This video of the emotional release and history of the chimpanzee Wounda by Rebecca Atencio and Jane Goodall went viral:

CONSEQUENCES BEFORE AND AFTER THE “FAME”

Chimpanzees are the most commonly apes used for this kind of shows. According to studies, such as the one by the University of Kent (2011), primates end with psychological problems such as:

• Self harm and mutilation
• Bone fractures and wounds
• Psychomotor deficit
• Malnutrition
• Development problems
• Abnormal behaviors such as ingestion of feces and urine
• Repetitive movements with no function (stereotyping)
• Decreased gestures to communicate with each other
• Hyperaggression
• Social phobia, fear, agoraphobia (phobia of open spaces and agglomerates
• Apathy
• Post-traumatic stress disorder
• Despression
• Inability to its development in conditions of freedom

“Animals are not clowns” campaign by Acção Animal y Liga Portuguesa dos Direitos do Animal (LDPA).

So they have the same consequences as any human can suffer in the same situation. We share 96.9% of our DNA with orangutans, 98.4% with gorillas, 98.8% with chimpanzees  and 99.9% with other humans.

Rehabilitation and socialization, it is not impossible in some cases, but it takes years and thousands of euros of effort, which does not justify its use in shows or keeping them as pets.

WHAT CAN YOU DO FOR PRIMATE CONSERVATION?

In June 2015, after years of struggle by Jane Goodall and other institutions, captive chimpanzees enjoy the same protection in the wild USA, they are considered endangered. Two chimpanzees have also been recognized as legal persons in court on his compulsory detention. Primatologists agree that the intelligence of a chimpanzee is equivalent to a 4 years old child and the debate is still alive on the inclusion of the great apes on Human Rights. Something is changing in consideration of our closest relatives, but is still clearly insufficient. What it is in your hands?

• Learn and share with your children, family and acquaintances capabilities and problems of these wonderful animals.
• Do not buy or accept a primate as a gift or souvenirs made from them, especially if you are traveling to foreign countries where the sale is cheap and easy. You can go to jail.

A simple key ring leads behind many deaths. Photo by WWF

• Do not attend circuses or give audience to television programs which use animals and participate in campaigns against it.
• Do not eat primate meat  (bushmeat)
• Avoid visiting zoos and other institutions that keep primates in captivity for profit.
• Do not use products tested on animals, especially cosmetics.
• Do not buy tropical wood or seek FSC certification of sustainable logging.
• Extend the life of electronic devices, especially mobile phones and recycle it as coltan and cassiterite it is used for manufacturing it.
• Report illegal wildlife trading
• Make donations to recovery centers or adopt a chimpanzee, also here
• Do not use products with palm oil, responsible for causing the deaths of dozens of orangutans daily.

Orangutan (Pongo spp.) (Literally, “man of the forest”) victim of deforestation for palm oil industry. Photo: unknown credit

REFERENCES

• Potts, Richard. Sloan, Christopher (2010). What does it mean to be Human? Ed. National Geographic Society.
• Bloom, Steve (1999). Dedicado a los primates. Ed. Köneman Verlagsgesellschaft mbH.
• The Jane Goodall Institute
• Mona Foundation
• FAADA
• Somos Primates
• Proyecto Gran Simio
• Investigación de los zoos en España
• CITES
• Is it possible to re-socialize abused primates?
• ¿Es verdad que no se debe mirar fijamente a los gorilas?
• Gorilapedia
• Zoo de Barcelona

• How YouTube has put the world’s only poisonous primates at risk

Lucy in the ground with diamonds

Surely one of the responsibles that you’re reading this post was the climate change that took place about 6 million years ago. The lifting of the Rift Valley caused a cooling and drying of sub-Saharan Africa, which favored the extension of the savannah at the expense of forests and the evolution of the first hominans who already walked by two feet. The most famous of them is undoubtedly Lucy. We encourage you to meet Australopithecus afarensis and the anatomy associated with bipedalism.

¿WHO WAS LUCY?

Just over 40 years ago, Donald Johanson discovered a partial skeleton (AL-288-1) 3.2 million old in Hadar, Ethiopia. It was the oldest hominan discovered and the bones belonged to an unknown species. At night, while celebrating the discovery with his team, the Beatles song Lucy in the Sky with Diamonds was playing in the cassette, and nicknamed the fossil remains. They belong to the species Australopithecus afarensis (Afar southern monkey).

Cast of Lucy in the Museum National d'Histoire Naturelle, Paris. (Photo: unknown author, Wikimedia)

Currently A. afarensis is one of the best known early hominans, as it have been found remains of hundreds of individuals, males, females and young ones.

ANATOMY

The average height and weight of A. afarensis was 1.05 m and 29 kg for females and 1.51 m and 42 kg for males, significantly smaller compared to us. Brain volume was also small, 387-550 cubic cm (similar to a current chimpanzee). The arms and fingers were longer than ours, which allowed them to climb easily in the trees, and the legs, though shorter, had characteristics that allowed bipedalism (walking on two feet) completely. The forehead was narrow and jaws were located forward (prognathism), with a large space for jaw muscles. Their diet was mainly herbivorous.

Reconstruction of Lucy by Elisabeth Daynès, with Laetoli footprint trails, in CosmoCaixa. (Photo: Mireia Querol)

ANATOMICAL FEATURES OF BIPEDALISM

A. afarensis already had the necessary adaptations to walk like us, though perhaps is not the older bipedal hominan: Orrorin tugenensis (6.2 to 5.6 million years) is aspiring to be one of the first members of the human race who walked upright .

Comparison between the skeletons of a current human (Homo sapiens), an A. afarensis and a chimpanzee (Pan troglodytes). (Photo: H. sapiens unknown author, A. afarensis John C. Phillips, chimpanzee Udo M. Savalli).

• Foramen magnum: the spinal cord goes through an opening in the skull, the foramen magnum. In the chimpanzee is located in the back of the skull, while afarensis has it in the base, which allows a vertical backbone settle.
• Backbone: lumbar and cervical area of the human backbone are more curved, we have a column with a “S” shape. The center of gravity is in the midline of the foot and allows spinal flexion during walking, therefore when chimpanzees walk on two feet, stagger for balance because they have a straight spine.
• Rib cage: A. afarensis still has a rather conical chest to accommodate a larger digestive system due to herviborous diet and better shoulder mobility to climb. H. sapiens have it shaped like a barrel, which facilitates the swing arm for better balance while walking and allows a better torso bending.
• Pelvis: human pelvis is shorter and wider than other primates, to allow better mobility with the base of the backbone, but the birth canal is narrow.
• Feet: A. afarensis toe, like ours, is aligned with the rest of the fingers, the sole is arched and a wide bead allows the foot to propel with the fingers and absorb shock when walking.
• Femur: due to bipedalism the joint surface is wide and the femur is angled toward the center of gravity. In the chimpanzee femurs are shorter, less inclined and with lower joints.

LAETOLI FOOTPRINT TRAILS

Laetoli footprint trails, Tanzania. (Photo: Sciencephoto Library)

2.000 kms further south where Lucy was found, in Laetoli (Tanzania), Mary Leakey discovered in 1978 the oldest known biped trail (3.6 million years) of probably 4 hominans who walked through the open savannah, with traces of other extinct animals like the horse Hipparion, a bird, a baboon and a centipede. The tracks are laid down in the ashes of the volcano Sadiman and are attributed to A. afarensis. There are 69 footprints, some overlapping others intentionally, perhaps as a strategy to leave no trace. The big toe is parallel to the rest of the fingers and a deep footprint and the bead is well marked, which confirms a completely bipedal stride.

But why has it been so important bipedalism in the process of humanization, towards the emergence of Homo sapiens? We’ll find out in the next article on human evolution.

Rreconstruction of A. afarensis by John Gurche. (Photo: Chip Clark)

 

REFERENCES

• Roberts, Alice. 2002. Akal. Evolución: historia de la humanidad.
• Turbón, Daniel. 2006. Ariel. La evolución humana.
• Cela Conde, Camilo José; Ayala, Francisco J. 2001. Alianza Editorial. Senderos de la evolución humana.
• Lucy, el fósil que reescribió la historia de la evolución humana
• Australophitecus afarensis (Smithsonian)
• Cambio climático motivó la evolución humana

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This publication is licensed under a Creative Commons:

Licencia Creative Commons Atribución-NoComercial-CompartirIgual 4.0 Internacional.

Who are the hominids?

Today’s article is dedicated to primates. We will talk about some of its key features, the classification of the living species and we will discover who the hominids and hominans are.

GENERAL CHARACTERISTICS OF PRIMATES

Primates are an order of placental mammals that appeared about 65 million years ago in the tropical rainforest. There are currently over 400 living species, most of them arboreal. Since there are no single trait that defines them, they are difficult to classify; so we have to consider a set of features, which are:

• Complex visual system: with frontally placed eyes, their vision is stereoscopic, allowing them to perceive the distance and depth with great accuracy. Most species can see in color.
• High mobility of the shoulder: allows an easy arm movement in all directions. Hands and feet have five fingers and opposable thumb (at least in hands) allowing them to grasp and manipulate objects with precision. Although some have claws, most have flat nails and all (except some orangutans) have a flat nail on the big toe.
• Torso and tail: several primates rest and move with an erect torso. Except apes, in some cases they have a prehensile tail, and can use it as a fifth limb.
• Brain size: besides some species of toothed whales, some primates have, in relation to the body, the largest brain of all mammals.
• Social organization: only orangutans, some lemurs and galagos are solitary, other primates are organized in complex social groups.

Gorilla eating (Gorilla sp.) where whe can see some of the characteristics. Photo: pixabay.com

 

CLASSIFICATION

The relationships among the different groups of primates were not clearly understood until relatively recently, so the commonly used terms are somewhat confused (mokeys, apes…). Modern cladistic classifies primates in two suborders, Haplorrhini (“dry-nosed primates”) and Strepsirhini (“wet-nosed primates“). A possible classification would be:

Primates taxonomy. Clic to enlarge. Created by Mireia Querol based in an image taken of humanorigins.si.edu.

Traditionally primates are classified into three groups: prosimians, monkeys and apes.

PROSIMIANS

Prosimians are the oldest primate group. They are distributed throughout Southeast Asia and Africa marginal islands. Prosimians include lemurs, lorises, galagos, indris, the aye-aye and tarsiers. They share the following characteristics:

• Claws instead of nails (they have at least a fingernail)
• Long snout with wet nose. They have the best sense of smell among primates
• More lateral orientation of the eyes than other primates. These are big and have good nocturnal vision
• Mobile pinna
• Minor brain proportion than other primates

Aye-aye (Daubentonia madagascariensis). Photo: Frans Lanting

 

Philippines tarsier (Carlito syrichta). (Photo: Kok Leng Yeo)

OLD AND NEW WORLD MONKEYS

The New World monkeys are distributed throughout Central and South America. They have a long, often prehensile tail. The muzzle is flat and the nostrils are situated in the side. They are completely arboreal. The best known representatives are marmosets, spider monkeys, capuchins, and sakis.

Male of White-faced saki (Pithecia pithecia). Photo: Charles Miller

 

The Old World monkeys are distributed throughout Africa and Asia. Usually they are bigger than New World monkeys. The nostrils are directed downward or forward. The Old World monkeys cover a wide range of species, such as macaques, baboons, mandrills, mangabeis, drills, colobus, proboscis monkeys, langurs …

Gee’s golden langur (Trachypithecus geei). Photo: Wikimedia

 

APES

Apes are divided into two families: Hylobatidae (gibbons and siamangs) and Hominidae (orangutans, gorillas, chimpanzees and humans). They are distributed throughout West and Central Africa and South and Southeast Asia, except humans: we are distributed all over the planet and habitats. Apes have a flat face, with the nostrils downwards and an anatomy that facilitates upright posture and materials handling, including the creation and use of tools in some species.

Bonobo (Pan paniscus). Photo: Pierre Fidenci

In conclusion, hominids are human beings (Homo sapiens) together with orangutans (two species: Pongo pymaeus and Pongo abelii), chimpanzees (Pan troglodytes), bonobos (Pan paniscus) and gorillas (two species: Gorilla gorilla y Gorilla beringei), because we all belong to the family Hominidae. The term also refers to all fossil species of this family, and therefore our ancestors, that we will discuss in future articles on human evolution. However, to refer exclusively to our evolutionary branch (including H. sapiens) the used term is hominans or hominas, which refers to a tribe (Hominini) of the Hominidae family.

REFERENCES

• Clutton-Brock, Juliet et al.  2002. Animal. Pearson Educación
• Roberts, Alice. 2002. Akal. Evolución: historia de la humanidad.
• The Enciclopedy of Life
• The Smithsonian Institution’s Human Origins Program
• Cover photo by Miquel Llorente

If you enjoyed this article, please share it on social networks to spread it. The aim of the blog, after all, is to spread science and reach as many people as possible.

This publication is licensed under a Creative Commons:

Licencia Creative Commons Atribución-NoComercial-CompartirIgual 4.0 Internacional.