Animals (also called Metazoa) are multicellular eukaryotic organisms that form the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and grow from a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from 8.5 micrometres (0.00033 in) to 33.6 metres (110 ft). They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology.
Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes—in which many groups of invertebrates are found, such as nematodes, arthropods, and molluscs—and the deuterostomes, containing both the echinoderms as well as the chordates, the latter containing the vertebrates. Life forms interpreted as early animals were present in the Ediacaran biota of the late Precambrian. Many modern animal phyla became clearly established in the fossil record as marine species during the Cambrian explosion, which began around 542 million years ago. 6,331 groups of genes common to all living animals have been identified; these may have arisen from a single common ancestor that lived 650 million years ago.
Historically, Aristotle divided animals into those with blood and those without. Carl Linnaeus created the first hierarchical biological classification for animals in 1758 with his Systema Naturae, which Jean-Baptiste Lamarck expanded into 14 phyla by 1809. In 1874, Ernst Haeckel divided the animal kingdom into the multicellular Metazoa (now synonymous for Animalia) and the Protozoa, single-celled organisms no longer considered animals. In modern times, the biological classification of animals relies on advanced techniques, such as molecular phylogenetics, which are effective at demonstrating the evolutionary relationships between taxa.
Humans make use of many other animal species, such as for food (including meat, milk, and eggs), for materials (such as leather and wool), as pets, and as working animals including for transport. Dogs have been used in hunting, as have birds of prey, while many terrestrial and aquatic animals were hunted for sports. Nonhuman animals have appeared in art from the earliest times and are featured in mythology and religion.
I'm not really sure that this fits under Biology, but oh well... I was wondering how animals, such as dogs, learn to speak their own language.
One would think there would be two possible explanations of how they do this: one being that they are born with an innate understanding of the...
If in an imaginary world, you had to create a (creatively and humorously) witty hydrid between any TWO single admired (or even disliked) animals listed below, what are the wittiest ones you'd create and what would be unique or funny about your animal hybrid ?
Fish.
Penguin.
Sea horse...
I have searched high and low for a ram, not the computer ram, an animal ram
for my avatar, just a face/head will do, but it will have to fit my character,
you know, powerful, pure, good natured, charitable, honest, etc, etc, so anyone seen my avatar ?
Anyone here an animal right's activist (not quite sure if this is the right term, the most general term being preferred)?
-Farm animals being enclosed/penned upin unsuitable living conditions (such as those associated with the big business meat industries)
-chemical experimentation on...
Let's say you have a hypothetical species of animal and on average, these animals reach sexual maturity at age 10, will breed from age 10 to age 20, and die at age 50.
Let's also say that there is an individual who is homozygous for a unique genetic disorder that will cause him to die at age...
While surfing web I have stumbled on a few video clips showing animal abuse, one was showing racoon type animal being skinned alive ,and the other was about snakes skinned alive too.
My question is: do those people think that meat of this animal is more tasty and "medicinal"? WTF ?? :frown:
Two unrelated teasers:
1- What animal(s) could you kill every single one of, and yet have more of them in a year's time?
2- What do Elephants have that help their species to survive that no other species has?
Hi. One of my friends is a vegan (yes, i know, but that's not the point) and she's very interested in product testing on animals...Namely, technology that can replicate it. See, she's looking for more information on how technology, machines or otherwise, might be as accurate of measuring...
In the thread Why this is still Amerikkka, there is a lively discussion of the extent to which many sub-Saharan countries are still economically undeveloped as a result of the genes of their inhabitants, the extent to which those genes are responsible for agriculture and sedantry animal...
http://www.nbc6.net/news/3591070/detail.html
This is Picture 17 of 21 from the link:
http://images.ibsys.com/2004/0729/3590966.jpg
Aside from the fact that the media is hyping all of this so much, what do you think is going on? Are these just a few isolated cases, or might we have some...
A Hairless Mexican dog, a coyote with mange, an armadillo without a shell, a hybrid? An interesting story with a [dead] body for evidence.
Be sure to watch the video.
http://www.woai.com/news/local/story.aspx?content_id=FAE91F84-A264-4AC3-8EA4-9097690CDEFC
Most of you have probably heard a phrase along the lines of "man the rational animal". I think that it is fairly obvious that this phrase is meant to refer to the the idea that man has rational abilities, not that he is impervious to irrational emotions. Perhaps it is supposed to suggest that...
This heated debate on animal testing happened in my English Class the other day. A large number of girls are against it. I personally am on the fence. So what's your take on the issue?
Say you have an animal and you swiftly decapitate it. As an organism, it is now dead (right?), but in what level (below organism) does death immediately set in? When an animal is swiftly killed, do all of it's organs immediately stop functioning? Would that organism's epidermis continue to...
I am wondering about the differences between plant vs animal cell division, mainly about cytokinesis.
Is the following a true generalization?
Plant daughter cells separate by forming membrane vesicles that line up in the center of the cell and fuse to form new plasma membranes.
Animal...
There is a lot of controversy over the morality of testing new products and procedures on non-human species. I seek to find out what everyone believes concerning this issue, as well as how much everyone knows about alternatives.
"The lamb had an odd teardrop-shaped cut at the hip area of its left leg, similar to other such cuts on animal deaths I have investigated in North America."
http://www.earthfiles.com/news/news.cfm?ID=562&category=Environment