Question

1. What are the common myths about evolution and why are they wrong?

2. Name and describe the three results of natural selection that can create changes in the percentages of alleles in a population?

3. What are the allopatric and the sympatric speciation? Give examples of each.

4. What are the two major types of barriers that result in reproductive isolation? Give several examples of each type that prevents the result of healthy, fertile offspring between two different species.

5. Trace our hominid ancestor tree (pick 5 ancestors) and include rough dates. What hominids are most closely related to us? When humans left Africa, what areas were colonized last?

6. How could genetic drift counteract natural selection? Be sure to give a real-world example.

7. What are the key components for natural selection? Give an example of each.

8. What are the major branch points for plant evolution?

9. What are the major branch points for animal evolution?

10. What are some of the major ways that the percentage of alleles in a population could change? Explain whether the process increases or decreases the variety of alleles.

Answer 1

A) First thing is every one thinks 'evolution just a theory'

According to the scientific method, a “theory” is an explanation grounded in a large amount of evidence. But Many people confuse the word “theory” with “hypothesis"

Second thing is 'evolution explains origin of life'

But actually evolution does not explain the origin of life, but how it developed after it appeared on earth.

And some one believes that evolution contradicts the second law of thermodynamics.

That is for an irreversible process in an isolated system, the thermodynamic state variable known as entropy (a term associated with disorder) is always increasing. But for evolution order is increasing.

This is wrong because the law applicable to closed system, and the order is decreasing in evolution.

B) There are directional, stabilising and disruptive selection.

In Directional natural selection an extreme phenotype is favored over other phenotypes, causing the allele frequency to shift over time in the direction of that phenotype.

In stabilising natural selection in which the population mean stabilizes on a particular non-extreme trait value.

In disruptive selection in which the population mean stabilizes on a particular non-extreme trait value.

C) In allopatric speciation groups from an ancestral population evolve into separate species due to a period of geographical separation.

Eg: Galapagos finches

In sympatric speciation groups from the same ancestral population evolve into separate species without any geographical separation.

Eg:Apple maggot fly is an example.

Apple maggot flies used to lay their eggs only on the fruit of hawthorn trees, but less than 200 years ago, some apple maggot flies began to lay eggs on apples instead.

So it lead to two species later.

D) Prezygotic and post zygotic are two major reproductive isolation.

Prezygotic includes temporal,behavioural,mechanical isolation

Post zygotic have genetic incompatibility, zygotic mortality, hybrid inviability, hybrid sterility, and hybrid breakdown.