Monkeys, lemurs, gorillas, apes and even we humans are part of an order called Primates. The reason why we are all included on the same order is very simple. We all share similar physical features.
- Primates are generally lively, clever, and very successful at adapting to different environmental opportunities, but comparing to other animals, primates do not offer any physical specialization;
- Primates use hands and feet for grasping;
- Very good vision but not so sharp sense of smell comparing to other animals;
- With a few exceptions, all primates present pentadactylism (five fingers on each hand and five toes on each foot);
- Significantly larger brain than ancestors and other current animals.
AS far as the oldest types of primates ever found, we have Archaic primates
dating 65-55.8 MYA, who proliferated in the Eocene and precursors to monkeys
and apes are dated to the Oligocene.
During the Eocene Epoch,
primates with larger bodies and bigger brains began to appear in the
fossil record. and most of the records from that time have some resemblance
with prosimians of today. Some other founds suggested that they were spending
more time in an erect position than before. By the end of the Eocene Epoch,
many of the prosimian species had become extinct, probably due to the cooler
temperatures that were starting to change the planet. That gave room for
the appearance of the first monkeys
during the transition to the next geologic epoch, the Oligocene
 | |||||
| 47 million year old Adapidae fossil from Germany (much of the soft tissue, includingfur, is fossilized) |
Since we mentioned the prosimian, let’s take a closer
look to what they are.
Prosimian are primates that include galagos, pottos, lemurs, bushbabies, tarsiers and lorises. Most of the animals of this group are located in Madagascar or Asia. Prosimian are more primitives comparing to other primates and some of their characteristics are:
·
Have a better sense of smell
than other primates and usually mark territory with smell;
·
Enhanced night vision;
·
Most of species are tree-dwelling and
that is reflected on their body features;
·
Prosimians produce a variety of calls to
communicate to one another;
·
Unlike other primates, prosimians
reproduce during a distinct breeding season.
Lemurs are an example that is included in the group of STREPSIRHINI, which would be a
subordinated division of the Prosimian Primates.
Lemurs are commonly found in Madagascar and some little
islands around it. They are divided into 9 genera and 22 species. They can be both diurnal or nocturne, and tend
to move slowly during the night, but communicate with each other use sound and
sometimes by smell. They eat a variety of fruits, plants and leaves but some of
them can eat insects too.
The mainland version of Lemurs
are Lorises, and they can be found in Asia and Africa.
Another subordinated division
of Primates is HAPLORHINI. Humans, monkeys, apes and tarsiers and
included in that group.
Some characteristics of this division are:
- Wide range of limb movement
- Lack of dietary specialization which is reflected in the teeth
- Animals in this group have lost the enzyme responsible for manufacturing Vitamin C
- Larger brain and primary sense is vision
Tarsiers.
- Small species exclusively found in Asia
- Biochemically more similar to anthropoids
- Eyes are about the same size as their whole brain which makes it difficult to move their eyes, but they are able to rotate their heads 1800
- Capability of jumping
- Unique dental formula (lack of toothcomb)
Anthropoids: Monkeys,
Apes, and humans
·
Larger brain comparing to body weight
·
Larger bodies
·
Reduced sense of smell and increased sense of
vision with forward facing eyes
·
More generalized dentition
·
Females present differences in the internal
reproductive anatomy
·
Longer gestation
·
Significant parental care
The monkeys are divided into
two different groups:
Platyrrhinii
·
Also known as new world monkey
·
Small, mid- size primates
·
Arboreal
·
Grasping tails
·
Known for the flat noses
Catarrhini
·
Old world monkeys
·
Downward noses
·
Have flat toenails and fingernails
·
Generally arboreal,
but with exceptions.
HOMINOIDEA – APES AND
HUMANS
- Hylobatidae (gibbons, siamangs)
- Pongidae (orangutans, gorillas, chimpanzees, bonobos)
- Hominidae (humans, and fossil humans)
- Some of them live in trees, but mostly found on the ground
- Developed brains and very intelligent
- No tail
- Arms are longer than legs (only in the apes)
- More complex behavior
- Enhanced Cognitive abilities
- Increased period of infant development and dependency
Gibbon
Gibbons are found in tropical areas with rainforests
mostly in Asia, India and Indonesia. Smaller than Great Apes, gibbons present
fewer differences between the male and the female sometimes having some
characteristics closer to monkeys, but it has evolved like the apes to lacking tails.
Orangutan
Orangutans are exclusively from Asia living in rainforest
areas. They have a large body with prominent mouth area, which allows them to
use their mouths for many different purposes. They also present a similar hand
to humans, with four long fingers and one thumb. While males are the
predominant, the females are very caring for their new born. Infants are very
completely dependent of their mother until approximately 2 years old.
Gorilla
Gorillas are found in central Africa, but are sadly in
danger of extinction. They are the largest of all primates, males can get up to
400 lb. Gorilla’s DNA is very similar to the human DNA.. They are very
intelligent and are able to lean new tasks, laugh, show emotions, have a strong
bond with the family, divide themselves into groups and some are able to use
tools ( For examples a stick to reach for ants under the ground ).
They usually knuckle – walk (uses the help of hands to
walk), but something they can also walk on only both feet. The mother is
responsible for raising the infant, but sometimes the male introduces the
infant socially.
Chimpanzee
Chimpanzees can be found in West and central Africa, but also are in danger of extinction due to the human population taking over their natural habitat. One of the closest living relatives to the humans, sharing a common ancestor. Chimpanzees also
knuckle – walk, but their feet are better designed for walking than the
gorillas, because bottom is broader and toes are shorter. Their behavior is
remarkable for having groups where there is a male leader that leads the rest
of the troop and they present an omnivorous diet. Interestingly, chimps sleep
an average of 9 hours per day. One interesting fact that is typical of the
chimps is the grooming, which is an activity based on picking each others
hairs looking for bugs and little insects. The average chimp spends about an
hour per day grooming another chimp. For them this is a social activity that
helps alleviate tension and straighten relations among group members.
Bonobo
Similar to chimpanzees but smaller. Specie is found in
central Africa, generally a lot less aggressive maybe do to their sexual active
lifestyle. They are capable of feelings such as kindness. Different than most
animals, the female has a higher social status and the mother tends to have a
connection with son all life.
Primate behavior has some similarities to other animal’s
behaviors, but mostly it differs from all the others. I found this very
interesting website that presents the different aspects of primate behavior,
comparing human with other primates in terms of communication, social
organization, and the ability of using tools.
Among all the different forms of socialization, the
mother – son bond is the most remarkable in the primates. This bond is strong
because the infant most of the times depends of the mother for feeding, getting
around, being introduced to social spaces and others. Most of the times this
bond is strong only at the beginning of the infant’s life, but in some cases
this bond can last forever.
Another important factor in the social organization is the
different forms of dominance. Life I mentioned before, the female is higher
socialize in the bonobos. But in most cases males will give up for females,
like if for example the female finds the food first.
Sadly, more than 90% of non-human primates are in danger of extinction, and most of the
time that is due to the human actions. At first the main cause was habit loss,
but recently that changed to human hunting.
Primate behavior:
There are two elements to be considered when studying
today’s primates behavior: Ecological and Evolutionary.
There is also a new field called behavioral genetics that
studies the of certain gene or hormone to the behavior changes, but stream has
to be closely analyzed considering the environment factors that also play a role on the behavior
of the species. Considering the evolution of the primates and that each species
evolved on its own directions, it is interesting that there are still some
similarities on the behavior.
One of the most known characteristics to primate’s
behavior is the social grouping. To understand how it became part of the
primate behavior it is important to consider how hard it was for ONE individual
to adapt to the natural selection changes in the environment, so in order to maximize their survival and
reproductive outputs they started organizing themselves in groups. Two
important factors could have been the main reason that brought these animals
together: predation pressure and the advantage of gaining information from one
another.
In early times,
these affirmations were hard to conclude without having real life evidence of
their behaviors, so one generation after ethology was developed, people started
studying primate behavior. Among all the studies that were being developed at
the time, the most interesting to me was Jane Goodall who went to Gombe in
Tanzania to live with chimpanzees and study their behavior by living in the
same environment as them for over 45 years. She is considered the world’s
foremost chimpanzee expert.
These early studies
allowed for lots of knowledge about how these animals live in social groups.
Social Organization
- Single female and her offspring type of family group (Orangutangus and small nocturnal prosimians.
- Monogamous Family Group which consists in adult male and female with their children - common for humans but not common for non-human primates.
- Polyandrous family group: The smallest New World monkeys, the marmosets and tamarins, form both monogamous and polyandrous family units.
- One male, several female type of group. That is to say, one male regularly mates and lives with more than one female at a time, this is the most common organization for non-human primates.
- Multimale and multifemale groups: The most common social group pattern among semi-terrestrial primates, commonly have a dominance hierarchy among both males and females.
- A fission-fusion society is one in which the social group size and composition change throughout the year with different activities and situations, commonly found as a pattern for chimpanzees.
Here are some
characteristics that would influence such social structures:
·
Body size – males tend to have a larger body
·
Type of diet, could be mostly fruit eaters or
small insect eaters
·
Predation
·
Distribution of resources
Personal Input
This was so far the most interesting subject of this
class, to me. I am highly interested in understanding the relation between
humans and the rest of the primates and understanding their similarities.
What I knew beforehand about primates was very small in
content comparing with my knowledge now. For example, I never thought creatures
such as tarsiers could be considered primates, but now I understand that in
some level, we are share similarities.
It is also interesting to know that despite behavioral
and physical similarities, we are all considered primates because of our DNA
proximity. To image that for example humans and chimpanzees have only 1.2
percent of genetic difference between them, it is pretty interesting and it
makes me wonder, why do we “treat” ourselves like such important species? Why do we “rule” the world like if any other
species would ever be as good? I believe if given the opportunity of learning
or maybe the need of adaption necessary to use more of their cognitive brain,
probably apes, chimpanzees and so on, would share a very close level of
intelligence as us humans.
One sad factor is that most of the non- human primates
are in danger due to human actions. It is pretty frustration to me to imagine
species that are genetically so close, species that shared the same ancestor
between 8 and 6 million years ago, loosing space on Earth to give more space to
humans. If instead we all took the time to understand them, like Jane Goodall did, we would see they are
closer to us than we can think of, and maybe it would feel wrong to destroy
natural habitat or hunt a species that reminds us of ourselves.
Unfortunately
we were studying these two chapters, the museums in the DC are were closed so I
did not have a chance to go see the primate exhibit, but I did read some very
interesting articles and websites during this time of research for this blog
post, and I will be sharing the most interesting ones with you.
Additional Information
In the class, we watched a video about KOKO the gorilla,
who was trained by Francine Patterson for several years, and learned how to use
and understand over a thousand signs based on
the American Sign Language. I loved that video and went on to research a
bit more about it. During my research I found a very interesting video about a
Bonobo called Kanzi and his sister. They both understand human speech and
communicate through lexigrams. This video gives a great background explanation
about bonobos, their natural habitat, their fossil records and recent
researches about their intellectual capability being very similar to our
own. I decided to share this documentary
as a part of my additional information:
Following this same aspect that the other primates are
able to think similarly to humans, my husband found this video on TED talk, and
shared it with me because he knew I was writing this blog post about primates.
This video is basically a presentation by Frans de Waal about moral behavior in
animals. Waal is a primatologist and ethologist, and in this video he talks
about this similar feeling animals share with humans of morality in some
specific situations and he presents examples that are mostly in the primates
area.
The video is funny, because it compares animal behavior with humans, but at the same time is very interesting to see how the animals behave in situations of unfairness, empathy and compassion.
The video is funny, because it compares animal behavior with humans, but at the same time is very interesting to see how the animals behave in situations of unfairness, empathy and compassion.
This next image, I found very interesting, because it
presents some of the closest to human primates all standing on a tree and a
brief description of each species.
Lastly, I work as a nanny part time to help pay for my
studies, and one of the kids I watch love this book about Chimpanzees from Jane
Goodall. I used to always read this
book, and I found it very interesting, but before this lecture about primates,
I did not really know who the writer was. After this lecture, I actually liked
the book even more, because it is a very simple to understand language, but
with lots of valuable information about chimpanzees and primates behavior in
general and very interesting book for the whole family. So I decided to add a link to some of her
books. I personally loved reading one of them ( The Watcher) and already order
some others.
