ANT101 Lecture 13: Primate Origins

Practice flashcards based on the lecture notes about primate origins and evolution.

What is the significance of primates in relation to placental mammals?

Primates are part of the expansion of placental mammals.

What are the five takeaway concepts in primate paleontology?

1. We’re Probably Here Because Dinosaurs Are Not

2. There Are Different Ways to Calculate the Timing of Splits

3. Fossil Data Has Limitations

4. We Don’t Know Where Some Types of Primates Emerged

5. We Don’t Know Why Primates Emerged.

What is genetic dating in the context of primate evolution?

Divergence times estimated by comparing DNA from different living species, counting genetic differences and assuming a constant rate of change.

How does the molecular clock contribute to our understanding of primate evolution?

It provides estimates of divergence times based on genetic data, generally concordant with fossil records.

What does the fossil record indicate about the presence of primates?

Many fossil primates are represented only by teeth, leading to gaps in the record.

What adaptations do monkeys and hominoids show in molar cusp patterns?

Monkeys show bilophodont patterns while hominoids display a Y-5 pattern on the lower molars.

What are the three hypotheses explaining why primates emerged?

1. Visual Predation Hypothesis 2. Angiosperm Radiation Hypothesis 3. Arboreal Hypothesis.

During which geological periods did the earliest fossil primates appear?

Primates date to the Paleocene and Eocene.

What are Plesiadapiforms?

Small, insectivorous mammals resembling tree shrews, which may be potential ancestors of primates.

What is the dental formula of Adapoids?

The dental formula of Adapoids is 2.1.4.3.

How does the size of Omomyoids compare to Adapoids?

Omomyoids are smaller than Adapoids.

What is the significance of the Miocene period for primates?

It is known as the 'Planet of the Apes' and marks the age of hominoids.

From where might platyrrhines have migrated to South America?

They may have migrated via a land bridge from North America or rafts from Africa.

What type of environments did the earliest anthropoids likely inhabit?

They likely originated in forested areas of North Africa or East/Southeast Asia.

Which primate is considered possibly ancestral to orangutans?

Sivapithecus species.

What is Gigantopithecus known for?

It is known primarily from teeth and mandibles, with large jaws possibly adapted for eating bamboo.

What specialized adaptations did Oreopithecus have?

It had very specialized dentition and may have been bipedal.

What time frame does the Miocene cover in relation to primate evolution?

The Miocene period is between 24 to 5 million years ago.

What marks the separation of great apes and what is debated about their origins?

Debate focuses on whether the ancestors of Great Apes evolved in Europe or Africa; likely Africa.

What is the dental formula for hominoids during the Miocene?

Hominoids exhibit a 2.1.2.3 dental formula.