10.2 - Phylogeny

Question 1

What does courtship behaviour allow for?

Answer 1

help animals attract mates through displays and signals that are species specific.

Question 2

What benefits are there for courtship? (3)

Answer 2

• It enables recognition of same species, leading to successful mating, production of fertile offspring, and raising of offspring.
• It prevents wasteful interspecies breeding.
• It maximises chances of successful reproduction, like in species where females only produce egg cells at specific times to determine if the female is at the receptive stage for mating.

Question 3

What is phylogenetic classification based upon? What does it show?

Answer 3

based on evolutionary relationships between organisms and their ancestors, classifying species into groups. It reveals how closely related organisms are.

Question 4

What are phylogenetic trees?

Answer 4

They map evolutionary relationships between organisms and their histories

The relative positions of branching points show distance of shared common ancestors. The relative distances between vertical lines shows closeness of species' evolution from common ancestral branches. The proximity of species to each other indicates the closeness of their evolutionary relationship.

Question 5

What did early classification depend upon?

Answer 5

relied only on visible features

Question 6

What evidence does modern phylogeny use? (4)

Answer 6

• Molecular comparisons - Comparisons between DNA and amino acids in proteins e.g. cytochrome C.
• Development studies - Comparisons of embryonic similarities and differences.
• Anatomical examinations - Comparisons of similarities in species’ physical characteristics e.g. from fossils.
• Behavioural analysis - Comparisons of similarities and differences between the behaviour of species.