Search results for: 'Presumed evolutionary branchings in the primate family tree Animation.'

Watch Later 1:29

By: HWC, Views: 2782

Presumed evolutionary branchings in the primate family tree. The first primates arose between 85 and 65 million years ago. The common ancestor of apes and hominids branched off from Old World monkeys about 23 million years ago. The hominid lineage, which includes humans and earlier humanlik...

Watch Later 0:51

Genetic distance between human groups

By: HWC, Views: 3527

One proposed family tree for modern humans. This family tree is based on nucleic-add hybridization studies of many genes and immuno-logical comparisons. Branch points show presumed genetic divergences. This data indicates that the greatest genetic distance separates humans native to Afri...

Watch Later 1:24

Evolutionary tree of life Animation

By: HWC, Views: 272

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Watch Later 0:48

Generalized life cycles for plants and animals Animation

By: HWC, Views: 440

But the life cycles of plants and animals differ in their details. In animals, a multicelled diploid stage gives rise to single-celled haploid gametes, the eggs and sperm. These gametes combine at fertilization to form a diploid zygote, which grows and develops into a new multicelled animal...

Watch Later 2:48

Darwin's Observation (Fossils, Galapagos Islands & Africa ) and Natural Selection (Adaptive Traits)

By: HWC, Views: 6546

Along Darwin's voyage, he made many observations. Each one added to his understanding of how organisms change over time. Darwin was already familiar with fossils and knew that many fossils were very different from living organisms. But, also there were some fossils that were very similar to li...

Watch Later 0:51

Interpreting a cladogram Animation

By: HWC, Views: 274

Using a cladogram to determine relative relatedness and whether the lungfish is more closely related to a human or to a trout. To determine the relative relatedness, we begin by tracing the branches from the human and the lungfish to the point where they meet. We'll call this node 1. Now...

Watch Later 3:42

Photosynthesis and Van Helmont Experiment

By: HWC, Views: 5912

All energy on Earth comes from a star, the Sun. Light must travel 160 million kilometers to reach Earth where plants capture this light energy and convert it to chemical energy in the form of sugars. This biochemical process is called PHOTOSYNTHESIS. The summary equation for photosynthesis is ...

Watch Later 0:43

Labor and Delivery - Postpartum Assessment

By: Administrator, Views: 418

The postpartum patient's emotional status plays a significant part in her recovery and her adjustment to her infant. Postpartum hospital stays are very brief, so nurses must make every encounter with the patient meaningful. Developing a systematic method of assessing the patient will save time an...

Watch Later 0:34

Dendrite Animation

By: Administrator, Views: 10042

Dendrites (from Greek δένδρον déndron, "tree"), also dendrons, are branched protoplasmic extensions of a nerve cell that propagate the electrochemical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. Electrical stimula...

Search Results