study of embryos and their development.

change in inherited characteristics over time.

model describing evolution as a slow process by which one species changes into a new species through a continuing series of mutations and variations over time.

humanlike primate that appeared about 4 million to 6 million years ago, ate both plants and meat, and walked upright on two legs.

early humans that likely evolved from Cro-Magnons.

body parts that are similar in structure and origin and can be similar in function.

a process by which organisms with traits best suited to their environment are more likely to survive and reproduce; includes concepts of variation, overproduction, and competition.

group of mammals including humans, monkeys, and apes that share characteristics such as opposable thumbs, binocular vision, and flexible shoulders.

element that gives off a steady amount of radiation as it slowly changes to a nonradioactive element.

a type of rock, such as limestone, that is most likely to contain fossils and is formed when layers of sand, silt, clay, or mud are cemented and compacted together or when minerals are deposited from a solution.

a group of organisms that share similar characteristics and can reproduce among themselves producing fertile offspring.

inherited trait that makes an individual different from other members of the same species and results form a mutation in the organism's genes.

structure, such as the human appendix, that doesn't seem to have a function and may once have functioned in the body of an ancestor.

the preserved remains or traces of an organism that lived in the past

method of determining the age of a fossil by comparing its placement with that of fossils in other layers of rock

compares the amount of radioactive element with the amount of non-radioactive element

can provide evidence about how closely related organisms are based on genetics

the first human-like primate

some characteristics are short, heavy bodies with thick bones, small chins, and heavy brow ridges; They lived in caves and used stone tools to hunt large animals they disappeared 30,000 years ago

have been found in Europe, Asia, and Australia and date from 10,000 to 40,000 years in age; They look like modern humans but were 1.6-7 meters tall; They lived in caves and made stone carvings. they buried their dead; They painted bison, horses, and people with spears on their caves

the first tool makers "handy-man"

first people to leave Africa, walked upright, and had control of fire.