Evolution Chapter 17 pt3

A change in habitat from rainforest to woody grassland, making food

_________,

may have been a selective pressure favoring larger brains in early hominins.

• patchy and seasonal

• more diverse

• easier to find

Larger brains require

_________,

and selection favored adaptations that helped provide them, such as an upright posture and using tools to dig and butcher.

• more energy and nutrients

• more social interactions

During the Pleistocene glaciations, selection favored adaptations for survival in harsh, variable environments, and

________

selection for larger brains became more frequent in the Homo genus than it had been in Australopithecines.

• directional

• stabalizing

• disruptive

Larger brains provided more selective pressure, and

___________

first appeared in the Homo genus.

• more sophisticated toolmaking and hunting

• a bipedal gait

• larger teeth, jaws, and cheek muscles

Indications of complex language use, such as ceremonial art, trade over long distances, and local experimentation with tool design, appeared only after brains reached the size of

______.

• Homo sapiens

• Homo erectus

• Homo habilis

Computer modeling suggests that the strongest selective pressures driving the evolution of intelligence in hominins have likely been

________

interactions, highlighting the value of skills such as tool making and use.

• ecological rather than social

• social rather than ecological

No other species uses language the way humans do. Scientists infer that language is adaptive, and they take several approaches to studying it. For example, studying

_____________________

may provide insight into the evolutionary precursors of human language.

• how primates communicate with each other

• communication by social insects to find resources

• the means of communication used by dogs and cats

. Another approach is to identify the underlying basis of human language by

(1)__________________

and studying

(2)__________

language production.

• (1) investigating genetic disorders affecting language

  (2) the genes influencing

• (1) observing the way slang is used in cultures

  (2) the acoustic properties of

• (1) manipulating subjects to inhibit language production (2) the written aspects of

Yet another way to tackle the problem is to investigate how the brain’s ability to manipulate language has changed over time by

• conducting phylogenetic studies to map brain evolution.

• building complex mathematical models of syntax.

• performing controlled experiments that disable speech

Two of these lines of research are similar in that they identify steps in language evolution, and in all of them researchers compare a group that produces standard human language to groups that

___________

for language.

• have less genetic capacity

• have a greater genetic capacity

• have lost the genetic capacity for