Biological Classification and Evolutionary Adaptations

This set of flashcards covers key concepts related to biological classifications, evolutionary adaptations, and the traits of early hominins.

What organisms are Acoelomates

Flatworms, Cnidarians, Ctenophores, Sponges

Examples of Pseudocoelomates include:

Nematodes.

What are the examples of Coelomates?

Annelids, Mollusks, Arthropods

Which Animalia has no circulatory system

Non-Protostomes, Flatworms. Nematodes

Which Animalia has an open circulatory system

Bivalves, Gastropods, Arthropods

Which Animalia has a closed circulatory system

Annelids, Cephalopods

What animals have no gut

Sponges

What animals have an incomplete gut

Cnidarians & Flatworms

What is the benefit of the notochord?

Better movement of the tail.

From early gnathostomes —>early tetrapods —> mammalia, what does the lower jaw go through

Mandibular Cartilage —> articular bone —> malleus(hammer bone)

From early gnathostomes —>early tetrapods —> mammalia, what does the upper jaw go through

Palatoquadrate —> quadrate —> incus (anvil)

From early gnathostomes —>early tetrapods —> mammalia, what does th hyomandibula go through

The Hyomandibula —→ Hyomandibula —→ stapes

Which anatomical structure is derived from the mesoderm?

Neurocranium.

What do facial bones derive from?

Neural crest cells.

Define quantitative traits.

Traits that are the result of the expression of many genes.

What characteristics define the first hominins?

Bipedalism and absence of tools.

What features distinguish Homo erectus?

Larger brains than the first hominins, but smaller than Neanderthals and sapiens.

What tools did Homo erectus potentially use?

Stone axes.

What are key features of Homo Neanderthals?

Large brains, prominent brow ridge, and sophisticated tool use.

How recent did Homo Neanderthals go extinct?

About 24k years ago.

What is a defining feature of Homo sapiens?

Fully bipedal and possess better tools.

What are the oldest known hominins?

Ardipithecus.

What kind of tools did Australopithecus fashion?

Primitive tools.

What is a challenge faced in increasing brain size?

There are limitations that prevent further size increase through GADD45G

What defines a coelomate?

An organism with a true coelom, a body cavity completely lined with mesoderm.

What does the Fst value measure?

The Fst value measures genetic differentiation among populations,

What does 0 and 1 mean for FST

0=identical

1= completely different

What are Quantitative Traits

Traits as a result of the expression of many genes

What is the significance of the term 'Neural Crest'?

A group of cells that contribute to the formation of various structures in vertebrates.

What defines bipedal locomotion?

Walking on two legs.

What characteristic did Homo sapiens have that distinguished them from other hominins?

Highly developed cognitive abilities and complex tool use.