Lecture 2 - Evolution and Man Flashcards Preview

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Flashcards in Lecture 2 - Evolution and Man Deck (20):
1

What is Evolution?

Change in the hereditary characteristics of groups of organisms over the course of generations-descent with modification from a common ancestor

2

What is a scientific theory?

In science a theory is a well substantiated explanation of some aspect of the natural world that incorporates facts, laws and tested hypotheses

3

How many species that have lived on earth are extinct?

More than 99% of species that ever lived on earth are extinct

4

Where did feathers of birds evolve from?

The feathers of birds evolved from the scales of archosaurs

5

What are cetaceans?

an order of aquatic, chiefly marine mammals, including the whales and dolphins.

6

what is cetacean evolution?

gradual reduction in the hindlimbs, increased mobility of the back. The most recent fossils resemble organisms alive today, whereas the increasingly older fossils progressively

7

What is the source of change and continuity in evolution ?

DNA

8

What is natural selection

Natural selection operates on heritable change favouring better adapted individuals.

9

What does a mutation in the insect gene ultrabithorax cause?

Mutation in ultrabithorax (gene in insects) cause the production of an ectopic set of wings through transformation of the halters.

10

What is a tetrapod?

any vertebrate having four limbs or, as in the snake and whale, having had four-limbed ancestors.

11

What are vertebrates?

belonging or pertaining to the Vertebrata (or Craniata), a subphylum of chordate animals, comprising those having a brain enclosed in a skull or cranium and a segmented spinal column; a major taxonomic group that includes mammals, birds, reptiles, amphibians, and fishes.

12

What is a gnathosome?

(Zoology) any vertebrate of the superclass Gnathostomata, having a mouth with jaws, including all vertebrates except the agnathans Agnatha = the class of vertebrates comprising the lampreys, hagfishes, and several extinct forms, having no jaws or paired appendages.

13

What is sickle cell anaemia

Sickle cell anemia is an inherited form of anemia — a condition in which there aren't enough healthy red blood cells to carry adequate oxygen throughout your body. Normally, your red blood cells are flexible and round, moving easily through your blood vessels. In sickle cell anemia, the red blood cells become rigid and sticky and are shaped like sickles or crescent moons. These irregularly shaped cells can get stuck in small blood vessels, which can slow or block blood flow and oxygen to parts of the body. There's no cure for most people with sickle cell anemia. However, treatments can relieve pain and help prevent further problems associated with sickle cell anemia.

14

What does HbA/HbS offer protection to ?

malaria

15

What are the malleus and incus?

Bones in the middle ear

16

How many cervical vertebrae do most mammals have ?

7

17

Which altered gene expression can affect rib formation?

the Hox gene expression

18

What can altered Hox 6 genes induce?

ectopic ribs

Hox genes implicated in controlling stem cell proliferation Patients with cervical ribs have a much greater incidence of childhood tumours 

Patients with cervical ribs present with multiple abnormalities - there is a very strong selection against people with cervical ribs during childhood. They do not reproduce 

19

By how much do the human and chimp genomes differ ?

1.23%

20

The theory of evolution is not contentious, what is it supported by?

It is supported by the fossil record

It is supported through comparative studies of living animals - these reveal striking similarities

It is supported through molecular biology studies

In science a theory is a well substantiated explanation of some aspect of the natural world that incorporates facts, laws and tested hypotheses

The theory evolution - The theory of gravity