LECTURE TWO

Question 1

Evolution of Complex Adaptation:

Answer 1

• New variations arise from random mutation.
  
  • Two kinds of variation: continuous and discontinuous.
  • Challenge: Each small step must be adaptive, leading to questions of irreducible complexity.

Question 2

Types of Variation

Answer 2

• Continuous: Gradual changes over time.
  
  • Discontinuous: Sudden, distinct changes.

Question 3

Irreducible Complexity

Answer 3

Example: What is 5% of an eye? Better than no eye.
- Raises questions about the step-by-step evolution of complex traits.

Question 4

Non-random Differential Reproduction

Answer 4

Selection acts on variations that arise randomly through mutation.
- Selection itself is non-random and favors traits that increase fitness.

Question 5

The Blending Problem: What maintains variation?

Answer 5

Darwin couldn’t explains how new variations continually arise and persist within populations.
Mendel’s SOLUTION: To resolve Darwin’s difficulties we need to understand the nature of inheritance: it is particulate, not a blending process.

Question 6

The Chihuahua problem: What can natural selection extend range of variation?

Answer 6

Did not understand the mechanisms of inheritance.
Solution: Can act on many genetic variations within a population → leading to the proliferation of traits. → Diversifying selection.

Question 7

How are biological traits inherited?

Answer 7

Mendel and particulate inheritance:
Genetics = system for the inheritance of biological information

Question 8

How does new biological variability arise?

Answer 8

Mutation=generation of new biological variability
Hidden variation
epigenetics= alteration in the phenotypic expression of genes w/o altering the structure of the DNA

Question 9

Principle of Segregation

Answer 9

parents pass on thier traits to their children each parent only gives one version of each traits.

Question 10

Principles of Independent Assortment

Answer 10

Traits are passed on to offspring independently of each other. (deck of cards)

Question 11

Phenotype

Answer 11

Outward physical expression of a trait

Question 12

Genotype

Answer 12

Genetic makeup of a trait

Question 13

Gene

Answer 13

The basic unit of heredity.

Question 14

Gametes

Answer 14

Sex cells (eggs/sperm) that pass genetic information from one generation to another.

Question 15

Monohybrid Crosses

Answer 15

Crosses involving one trait.

Question 16

Dihybrid Crosses

Answer 16

Crosses involving two traits.

Question 17

Principle of Segregation

Answer 17

Traits are controlled by pairs of alleles that segregate (separate) during the formation of gametes. For each trait, offspring inherit one allele from each parent.

Question 18

Homozygous

Answer 18

Having the same alleles for a trait.

Question 19

Heterozygous

Answer 19

Having different alleles for a trait.

Question 20

Prunnett Square

Answer 20

A tool used to calculate all possible combinations of genotypes in offspring given the genotype of parents

Question 21

Principle of Independent Assortment

Answer 21

Alleles of different genes assort independently during gamete formation.

Question 22

F1 Generation

Answer 22

First offspring (hybrid) generation.

Question 23

F2 Generation

Answer 23

Second offspring generation.

Question 24

Simple Mendelian Traits

Answer 24

Traits controlled by one gene producing one trait.

Question 25

Exception to Mendel’s Postulates

Answer 25

Phenotypic variation produced by genetic makeup of an individual or environmental/developmental effects.