Week 1 Flashcards

Question

Evolution: What is evolution? Darwin & Wallace

Answer 1

Charles Darwin (1809-1882) “On the origin of species” (1859) considered the foundation of evolutionary biology  Natural selection - different genomes & then mutations = ^ survival  Evolution: Gradual change in structure of physiology of a species – generally producing more complex organisms – as a result of natural selection Natural selection theory can be attributed to Charles Darwin AND Alfred Russel Wallace  Wallace had the idea during a fever in 1858  However, Darwin had been working on it for 20 years in private e.g. the pepper moth

Answer 2

- Vertebrate brains are similar in organization (frogs, crocodiles, sharks…) - All vertebrates have a forebrain, midbrain & hindbrain (but do have other nuances) -  Brain areas may be specialised in distinct ways in response to environmental constraints * e.g., crocodiles have huge olfactory bulbs (brain area for smell)

Answer 3

 Proportion of the different areas changed (e.g. prefrontal cortex to accommodate more complex interactions)  Folding of cerebral cortex increased

Answer 4

there is no link between brain size and behavioural complexity (e.g. how elephants have bigger brains) BODY SIZE PROPORTIONS MATTER. -  There is a relationship between proportional brain size and complexity of behaviour  Human brain is proportionally larger than any other large animal (although Shrew's have 3.3% of their body as brains...)

Answer 5

○ 1. Australopithecus robustus  2. Homo habilis  3. Homo erectus  4. Homo sapiens neanderthalensis  5. Homo sapiens sapiens The high, straight forehead of modern humans superseded the prominent brow ridges of ancestors due to expansion of cortex, especially prefrontal cortex, in our species

Answer 6

- Size increased in primates -  Is flexible & has almost infinite learning abilities -  Reflects growing complexity of social lives  Growth of certain parts of cortex responsible for social skills (e.g., language) because they improved this ability (includes all the lobes)

Answer 7

- Developed greatly in primates -  In other species it is primarily for voluntary motor control -  In humans: Responsible for unequalled planning & abstract reasoning abilities MODERN RESEARCH:  Humans’ superior abilities are attributable to other specialized cortical regions & denser inter-connections between prefrontal cortex & rest of brain

Answer 8

Humans have larger volume of white matter in PFC White matter provides greater connectivity between PFC & rest of brain (compared to other species) Connectivity is vital for working memory functioning

Answer 9

Increase in cortex folding has been a major factor in brain evolution Folding = cortical surface area to fit inside the skull Allows better organization of complex behaviours

Answer 10

Changes to gene expression induced by environmental factors.

Answer 11

The principle that the best way to understand a biological phenomenon (a behavior or a physiological structure) is to try to understand its useful functions for the organism.

Answer 12

The process by which inherited traits that confer a selective advantage (increase an animal’s likelihood to live and reproduce) become more prevalent in a population.

Answer 13

Can be beneficial - variety is an advantage for species; adaptation

Answer 14

human - 2.3% Elephant - 0.2% Shrew - 3.3% What counts, as far as intellectual ability goes, is having a brain with plenty of neurons that are available

Answer 15

A slowing of the process of maturation, allowing more time for growth; an important factor in the development of large brains.