Chapter 2 (Course of Human Evolution, Human Evolution, Human Brain Evolution, Epigenetics) Flashcards
What is a species?
Any group reproductively isolated from other groups due to the inability to mate, biological differences, history, geographic separation [finches on the Galopagos] or courtship rituals (dogs unable to mate due to behavioural differences).
What are chordates?
Animals that have dorsal nerve cords
Homologous traits in animals that are similar are due to ———
Common ancestor (sleep cycling, periods of inactivity.)
Analogous traits in animals that are quite different is due to ———
Convergent evolution — shark (fish), penguin (bird), dolphin (mammal): sharing trait of streamlined appendages due to sharing a common environment.
What mutation may be responsible for why humans are able to use language?
High motor sequencing — especially in vocal tracts and hands — language (FOXP2)
Brain size is not a good indicator of intelligence, what is?
Brain stem to cerebrum ratio
Our genes are encoded on the ________ , and they are expressed by making ——— the DNA which are then translated into ———.
DNA; RNA; Protein
The study of epigenetics assesses how the environment interacts with our genes, and how the environment can act to control the likelihood of gene expression. Which of the following are considered epigenetic mechanisms that act to control gene expression?
a. Histone modification allowing for DNA to be more or less exposed for gene expression. Can happen due to lifestyle (diet, caffeine, exercise, sleep, etc.).
Expression of non coding RNA which may cause degradation of mRNA of transcribed genes.
DNA modifications (like methylation), which may impede gene transcription process.
Twin Studies & epigenetics
same genomes, same DNA, don’t always see concordance between twins throughout their lifespan (one gets cancer, one does not). Differences in environment/lifestyle leads to changes in epigenetic markers.
