Seven things about evolution
What is evolution?
All posts tagged with explainer
Seven things about evolution
What is evolution?
Group life in primates
Primates form different kinds of groups. While there is variation within every species, each species has its own typical range of group sizes. Primate groups...
Human and ape feet
At this station, you’ll find some articulated human feet. “Articulated” means that the bones are assembled together at their joints – two bones that articula...
Piltdown
Here you will find a cast of the Piltdown specimen. Both the skull and mandible were real bone; the problem is that the skull was human and the jaw orangutan...
Neandertal postcrania
Neandertals were very robustly built. This means that they had relatively thick bones, with thick layers of cortical bone. It also means they had relatively ...
Neandertal cranial anatomy
The Neandertals were Late Pleistocene inhabitants of Europe, and their skeletal remains were among the first fossil humans that scientists recognized as repr...
Modern human crania
By the end of the Middle Pleistocene, people throughout the inhabited world had attained brain sizes in the range of living people. Technology had ad- vanced...
Understanding population differentiation
This lab has a take-home assignment, which is worth three points when you turn it in at next week’s lab section.
Measuring differences between populations
When individuals mate locally, different populations tend to diverge from each other in the frequencies of their alleles. Genetic differences between populat...
Measuring population subdivision
The basic measure of genetic difference between two populations is the statistic, FST. In genetics, the term F generally stands for ``inbreeding’’, which ten...
Cranial features and race
Individuals whose ancestry derives mostly from different parts of the world sometimes have different cranial features. Forensic anthropologists have studied ...
Why do people differ in skin color?
The color of human skin is determined by the amount of two pigments, eumelanin and pheomelanin. These pigments are the basic ones underlying all kinds of col...
Sex and the mandibles of early hominins
Determining sex from human mandibles (as you will do in another part of this lab) depends on a series of characteristics that tend to differ between male and...
Meet Homo heidelbergensis
The Mauer mandible comes from just southeast of Heidelberg, Germany, and was found in ancient sands deposited just more than 600,000 years ago. Upon its desc...
Mandibles and sex
The mandible can provide important evidence in assessment of sex from skeletal remains. Male mandibles are generally heavier and larger than female mandibles...
Determining sex from the cranium
The cranium has a very distinctive shape, which varies between people to some extent. Some features that vary between individuals in their size or shape are...
The occipital bone
The cranium includes all the bones of the head. Altogether, there are 26 cranial bones plus the mandible. Except for the mandible, these bones mostly are fus...
The frontal bone
The cranium includes all the bones of the head. Altogether, there are 26 cranial bones plus the mandible. Except for the mandible, these bones mostly are fus...
African Homo erectus
This station includes several casts of early fossil Homo erectus, from the Early Pleistocene of Africa. These include:
Meet Homo habilis
This station has several of the key cranial specimens of Homo habilis, together with Sts 5, the representative of Australopithecus africanus. The H. habilis ...
Structure of the pelvis
The pelvis is a complex made of three bones: the sacrum and the left and right os coxae, also called “innominate” bones. The sacrum forms the posterior part ...
Sexual dimorphism of the pelvis
The pelvis is the most accurate indicator of sex in the human skeleton. Its central role in the birth process means that the pelvis has several shape differe...
Meet Australopithecus africanus
This station has several casts of remains attributed to the species, Australopithecus africanus. This was the first australopithecine species discovered, and...
Bipedality and the pelvis
Humans are bipeds. The pelvis in humans has undergone radical changes in orientation and shape compared to other anthropoid primates. Many of these changes s...
Tooth wear
Teeth have a close association with longevity. Enamel is the hardest substance in the body, but it does break, wear out, and is sometimes attacked by microbe...
Paleopathology
Often the skeleton bears signs of disease or injury that occurred during an individual’s lifetime. Not every disease affects bone, but some have highly recog...
Long bone development
The long bones grow in parts. Early in fetal development, the bones are formed from cartilage. Bone tissue forms as special cells (called osteoblasts) lay do...
Meet Aegyptopithecus
At this station are casts of Aegyptopithecus zeuxis. This species comes from the Oligocene, approximately 30 million years ago. It is from the Fayum fossil b...
Incisors
The incisors are the front teeth. They are basically flat and have a blade-like occlusal surface. Each quadrant has two incisors.
Deciduous teeth
Like most mammals, humans have two sets of teeth. The first set is called the deciduous dentition, but you probably know these as “baby teeth.”
Canines
The canine teeth in humans range from pointy-shaped to incisor-like in shape. There is only one canine in each quadrant, and it is the third tooth just dista...
Wisdom teeth
Most humans have three molars, but many — especially in America — have their third molars (called wisdom teeth) extracted. Some people do not develop third m...
Premolars
The premolars are directly distal to (behind) the canines. Generally there are two premolars in each quadrant. Counting backward from the front of the jaw, t...
Premolars in primates
Different kinds of primates have different numbers of premolars in their dentitions. The ancestral number of premolars in primates is three in each quadrant ...
Molars
The most distal teeth are molars. Most humans have three molars, but many — especially in America — have their third molars (called wisdom teeth) extracted. ...
The temporal bone
The cranium includes all the bones of the head. Altogether, there are 26 cranial bones plus the mandible. Except for the mandible, these bones mostly are fus...
Size of the external auditory meatus
This is a very simple lab station. The size of the opening for the ear canal, called the external auditory meatus, is larger in humans than in most other kin...
Earlobes
The form of the earlobes varies in humans. At one extreme, the lowest point on the earlobe is attached to the flesh of the cheek. If not, the earlobe is to v...
Genetic variation and the Hardy-Weinberg proportions
The fundamental information about genetics for any individual is her genotype — the alleles that she has. But genes in populations can be considered in other...
Meet Gorilla gorilla
The gorilla is the world’s largest living primate. Gorillas are presently distributed broadly across West and Central Africa, in forested areas where human a...
Humerus
The bone of the upper arm is called the humerus. It articulates with the scapula at the shoulder joint, and the radius and ulna at the elbow.
The different types of vertebrae
The spine extends from the head to the sacrum, and in most people consists of 24 vertebrae. The vertebral column can be divided into three segments:
The anatomy of a vertebra
Each vertebra has several parts. The most important are:
Reading a genetic map: the beta-globin gene cluster
A genetic map shows the location of genes and other DNA elements on a chromosome. The Human Genome Project created a genetic map that lists more than 3 billi...
Primate vertebral numbers
Between the skull and the sacrum, humans have 24 vertebrae. Well, most humans, anyway. Sometimes humans have a few more or less.
Statures of fossil Homo
Homo erectus and Neandertals were more or less human-sized. That may not be saying much, since we are so variable in stature ourselves.
Heritability and stature
Tall parents tend to have tall children.
Tibia and fibula
The tibia and fibula are the bones of the lower leg. The fibula forms the lateral part of the ankle joint, preventing dislocation in that direction.
Predicting stature from bone measurements
Anthropologists have collected data from many populations in the world, showing the relationship between the parts of the skeleton and body size and stature....
Eye pigmentation and allele frequencies
Eye pigmentation in humans varies along a spectrum of colors from dark brown, through lighter brown, hazel, and green, to light blue. These differences are c...
Meet Australopithecus robustus
The region just north of Johannesburg, South Africa, is a formation of ancient limestone in which groundwater has formed numerous caves and sinkholes. Some o...
Teeth
Goals:
Incisors
The incisors are the front teeth. They are basically flat and have a blade-like occlusal surface. Each quadrant has two incisors.
Bones of the cranium from the front
The cranium includes all the bones of the head. Altogether, there are 26 cranial bones plus the mandible. Except for the mandible, these bones mostly are fus...
Bones of the cranium from below
TemporalThe lower sides (left and right) of the vault, including the ear opening, or external acoustic porus. OccipitalThe rear and base of the skull, inclu...
Biological anthropology laboratory manual
These pages are the exercises for a laboratory in introductory biological anthropology.
Founder effect
A founder effect is caused by genetic drift in a small number of initial founders of a new population.
What does it mean for a trait to be heritable?
Tall people tend to have tall parents. The height of the body, called stature, is one of the most obvious phenotypic traits in human populations. Anyone who ...
Genetic drift
If everyone in a population lived a long life, mated, and reproduced absolutely equally (two offspring per person), then the population size would never chan...
Genetic variation and the Hardy-Weinberg formula
The fundamental information about genetics for any individual is her genotype. The genotype for a single genetic locus is simply a list of two alleles, wheth...