Mammals and Human Evolution Practice Flashcards

Vocabulary-style flashcards covering mammal characteristics, primate traits, and the evolutionary history and species of hominins based on lecture notes.

6000

The approximate number of mammal species on Earth.

Mammary glands

Milk-producing glands that are a characteristic of mammals.

Keratin

The protein that makes up the hair of mammals.

Endothermic

A characteristic of mammals where they generate and maintain internal body heat.

Internal Fertilization

The method of reproduction where fertilization occurs inside the body, characteristic of mammals.

Differentiation of teeth

A characteristic of mammals where teeth are specialized for different functions.

Monotremes

A group of mammals that lay eggs, including platypuses and spiny anteaters.

Marsupials

A group of mammals, such as kangaroos and koalas, that complete development while nursing.

Eutherian

Placental mammals that complete their embryonic development within the uterus.

Platypuses

An example of a monotreme mammal that lays eggs.

Spiny anteaters

An egg-laying mammal belonging to the monotreme group.

Opossums

A type of marsupial mammal mentioned in the notes.

Kangaroos

A specific marsupial that completes its development while nursing.

Koalas

A marsupial mammal listed alongside kangaroos and opossums.

Uterus

The organ where Eutherian (placental) mammals complete their development.

Sloth

An example of an Eutherian mammal mentioned in the transcript.

Flexible fingers and toes

A primate trait where digits are long and able to grasp objects.

Shoulder and hip joints

Joints in primates that allow a wide range of limb motion for jumping, running, and scampering.

Forward-directed eyes

An anatomical feature of primates providing color vision and depth perception.

Large advanced brains

A primate characteristic that facilitates the ability to learn and communicate.

Parental care

Behavior that increases in primates because they typically bear only one baby at a time.

Opposable Thumb

A thumb that is mobile and separate from the fingers, used for grasping and precise manipulations.

Prosimians

One of the two groups of primates, which includes lemurs and is described as premonkey.

Lemurs

Arboreal primates that belong to the Prosimian group.

Arboreal

A term describing a tree-dwelling lifestyle, characteristic of lemurs.

Anthropoids

The group of primates that includes monkeys, apes, and humans.

Small teeth

A characteristic that distinguishes humans from their close relatives.

Upright Posture

A physical trait of humans that involves standing and walking vertically.

Intricate behavior

Complex social and individual actions that characterize humans.

Tool making

A skill involving the creation of implements, characteristic of humans.

Language

A complex communication system used by humans.

Monkey intelligence

Described as differing from human intelligence by degree, not by kind.

Hominoid

A primate group consisting of great apes and humans.

Hominins

A group formerly called hominids that are more closely related to humans than to chimps or gorillas.

Australopithecines

An extinct group of hominins mentioned in the primate classification.

Genus Homo

The genus to which humans belong; all species in this genus except Homo sapiens are extinct.

6 MYA

The approximate time when hominins split from chimpanzees.

Chimp aggression

A behavioral trait of chimpanzees mentioned in the notes.

4 MYA

The time when hominins descended from the trees.

3.5 MYA

The approximate time when hominins became bipedal.

1.9 million years ago

The time when hominins began to walk long distances.

Homo, Australopithecus, Ardipithecus

The three specific genera of hominids mentioned in the lecture.

$$98.5\%$$

The percentage of the human and chimpanzee genomes that are identical.

$$20$$

The approximate number of extinct hominin species discovered by paleoanthropologists.

Ardi

The nickname for the hominin Ardipithecus ramidus.

$$4.4 \text{ million years}$$

The age of the Ardipithecus ramidus fossil known as Ardi.

Ardipithecus locomotion

Characterized by the ability to walk upright and efficiently climb trees.

Ardi's brain size

Described as being similar to that of chimpanzees.

Australopithecus

A genus of hominins characterized by larger teeth and smaller brains compared to modern humans.

Sexual dimorphism

A physical difference between sexes where males are larger than females, observed in Australopithecus.

Lucy

A specific Australopithecus afarensis fossil discovered in 1974 in Ethiopia.

3.2 MYA

The time period during which the hominin Lucy lived.

Ethiopia

The country where the Lucy fossil was found.

Australopithecus afarensis

The species that walked upright but stood only $1\,m$ high with a brain size of chimpanzees.

Homo habilis

The earliest fossils placed in the genus Homo, dating from $2.4$ to $1.6 \text{ million years}$ ago.

Handy man

The literal meaning of the species name Homo habilis.

2.5 MYA

The approximate time when tool making began to be practiced.

Stone tools

Items found with Homo habilis that led to its naming as handy man.

Australopithecus anamensis

An early hominin species shown on the timeline around $4.0$ to $4.5 \text{ million years ago}$.

Kenyanthropus platyops

A hominin species listed on the timeline as existing around $3.5 \text{ million years ago}$.

Paranthropus boisei

A hominin species appearing on the timeline between $2.5$ and $1.0 \text{ million years ago}$.

Homo ergaster

A hominin species from $1.9 \text{ MYA}$ with a brain size twice that of apes but half that of modern humans.

Homo erectus

A species existing from $1.8 \text{ MYA}$ to $300,000$ years ago that made stone hand axes and used fire.

Fire

A tool or element used by Homo erectus according to the lecture notes.

Large stone hand axes

Tools made by Homo erectus.

780,000 years ago

The age of a Homo erectus fossil discovered in Europe.

Neanderthals

Robust hominins with larger, more worn teeth who lived $400,000$ to $38,000 \text{ years ago}$.

Robust

The term used to describe the body type of Neanderthals relative to humans.

400,000 to 38,000 years ago

The time period when Neanderthals lived throughout Europe and Asia.

195,000 years ago

When Homo sapiens first appeared in Africa.

115,000 years ago

The date of the oldest Homo sapiens fossils found outside Africa, located in the Middle East.

Middle East

The location of the oldest Homo sapiens fossils outside of Africa.

15,000 years ago

The timeframe when humans first arrived in the New World.

Bipedal locomotion

The ability to walk on two legs, distinguishing humans from other apes.

Symbolic thought

An advanced mental capacity first displayed by Homo sapiens.

Artistic expression

A characteristic of Homo sapiens that distinguishes them from other apes.

Reduced jawbones

A physical change in Homo sapiens involving the jaw and jaw muscles.

Shorter digestive tract

A physiological trait of Homo sapiens compared to other apes.

77,000-year-old carving

An artistic carving found in South Africa in 2002, showing symbolic thought.

10,000 years ago

The approximate time in history when agriculture began.

6,000 years ago

The approximate time when metal tools began to be used.

5,000 years ago

The approximate time when the pyramids were constructed.

Multiregional Hypothesis

The theory that Homo sapiens evolved in each region from local populations of Homo erectus.

Out of Africa Hypothesis

Also called the replacement hypothesis, it claims Homo sapiens evolved in Africa and replaced regional populations globally.

Replacement hypothesis

Another name for the Out of Africa Hypothesis regarding the origin of modern humans.

100,000 years ago

The timing of the second migration of Homo sapiens from Africa in the Out of Africa Hypothesis.

Sahelanthropus tchadensis

One of the earliest hominin species listed on the timeline, around $7.0 \text{ MYA}$.

Orrorin tugenensis

A primitive hominin species shown on the chart living around $6.0 \text{ MYA}$.

Paranthropus robustus

A species that existed around $1.5$ to $2.0 \text{ million years ago}$ according to the hominin chart.

Homo neanderthalensis

The scientific name for Neanderthals as listed on the evolution timeline chart.

Homo rudolfensis

A species shown on the genus Homo timeline roughly between $2.5$ and $2.0 \text{ MYA}$.

Australopithecus africanus

A hominin species shown on the timeline between $3.0$ and $2.5 \text{ MYA}$.

Australopithecus garhi

A species shown on the hominin timeline around $2.5 \text{ MYA}$ near the appearance of Homo.

Placental development

The process by which Eutherian mammals develop in the uterus.

Keratinized hair

Hair made of keratin, a defining trait of mammals found in slide 1.

Long flexible toes

A physical characteristic of primates used for grasping.

Depth perception

Visual ability provided by the forward-directed eyes of primates.

Mobile thumb

A description of the opposable thumb in primates, being separate from other fingers.

South Africa

The location where a $77,000$-year-old artistic carving was found.

New World

The region where humans arrived sometime before $15,000 \text{ years ago}$.