Young-earth creationism and the kinds of animals

Genesis 1:20 God said, “Let the waters swarm with swarms of living creatures, and let birds fly above the earth in the open expanse of sky.” 1:21 God created the large sea creatures, and every living creature that moves, with which the waters swarmed, after their kind, and every winged bird after its kind. God saw that it was good. 1:22 God blessed them, saying, “Be fruitful, and multiply, and fill the waters in the seas, and let birds multiply on the earth.” 1:23 There was evening and there was morning, a fifth day.
1:24 God said, “Let the earth produce living creatures after their kind, livestock, creeping things, and animals of the earth after their kind”; and it was so. 1:25 God made the animals of the earth after their kind, and the livestock after their kind, and everything that creeps on the ground after its kind. God saw that it was good. 

7:1 Yahweh said to Noah, “Come with all of your household into the ship, for I have seen your righteousness before me in this generation. 7:2 You shall take seven pairs of every clean animal with you, the male and his female. Of the animals that are not clean, take two, the male and his female. 7:3 Also of the birds of the sky, seven and seven, male and female, to keep seed alive on the surface of all the earth. 7:4 In seven days, I will cause it to rain on the earth for forty days and forty nights. Every living thing that I have made, I will destroy from the surface of the ground.”
7:5 Noah did everything that Yahweh commanded him. (World English Bible, public domain.)

Young-earth creationists, of which Answers in Genesis is the most prominent organization, believe that there was a world-wide flood, occurring about 2348 BC, and that the land animals, including land-based birds, have all descended from the animals that Noah and his family had in the ark with them.

Saving all of the animals causes what seems to be an insurmountable problem for young-earth creationists. How did all of these creatures fit on the ark, and how was it possible to feed them? The answer, from Answers in Genesis, is that there were about 137 kinds of animals, and all of the types we have today descended from them. (This doesn't include insects -- at least some young-earth creationists believe that they weren't taken on the ark. Another estimate from Answers in Genesis is that there were about 1500 kinds of animals on the ark. I'm not clear on why the difference, although the larger estimate is said to have included "flying creatures." Perhaps the lower estimate doesn't include them.) It is doubtful that the Genesis word usually translated "kind" corresponds to any of the categories used by today's taxonomists. Young-earth creationists do not claim that it does.

How many species of animals are there now?
This source, citing an authoritative textbook, says that there are currently 5,416 species of mammals on earth. (This presumably includes water-living mammals, which, according to young-earth creationists, were mostly or entirely not found on the ark. The Answers in Genesis belief is that extinct animals from ancient times, such as the saber-toothed tiger, would have descended from animals on the ark, too.)

This source indicates that, until recently, it was thought that there were 9,000-10,000 species of birds, but that this number is an underestimate, and that there are perhaps twice that many. This source indicates that there are about 7,000 species of amphibians. This source indicates that there are about 10,793 species of reptiles. (This research article proposes that there were 11 kinds of turtle on the ark, which have given rise to 313 living species, and 3 kinds of alligator/crocodile, giving rise to 25 current species.) Using 9,000 as the number of species of birds, and 4,800 as the number of species of land mammals, there are about 31,500 species of birds, mammals, amphibians and reptiles now on earth. There have been some extinctions within recorded history -- dodos, moas, the marsupial tiger, dinosaurs -- yes, Answers in Genesis proposes that dinosaur kinds were on the ark -- and others, which would add to the number of species that must be accounted for. Young-earth creationists believe that no more than about 1,500 kinds of animals became 31,500, or more, species, within the last 4,366 years. That means that, on average, each of those 1,500 kinds evolved into 21 species over that period, and that number is probably an underestimate. That's an astounding claim!

Here's a brief statement of the Answers in Genesis position, with a diagram of part of the "cat kind." The diagram indicates that the cat kind of animals, on the ark, evolved into lions, house cats, jaguars and cheetahs. (And, presumably, servals, ocelots, leopards, tigers, including saber tooth tigers, and more.)

R. Joel Duff has written about these beliefs of young-earth creationists, and finds them wanting, for a number of reasons. Some of my criticisms, listed below, are derived from his article:

1) Answers in Genesis, which rejects evolutionary mechanisms for the origin of large groups of organisms, over long periods of time, wants us to believe that evolutionary mechanisms are responsible for an astounding unfolding of many species, over a few thousand years. Answers in Genesis does not say "evolutionary mechanisms" much, or at all, but they are really relying on natural selection for the unfolding of species from ancestral kinds.
2) One criticism of main-stream evolutionary thought, by young-earth creationists, is that some fossil links are missing. But there are no known fossils, from the last 4,366 years, of any of the proposed species explosions after the Ark landed. Furthermore, cave art doesn't show such transitional forms. They are missing!
3) The Bible seems to describe lions, and other animals of Bible times, as if they looked and acted as they do today. Samson encountered a lion in about 1,100 BC, so the cat kind, according to Answers in Genesis, would have diversified to about what it is today in a mere 1,300 years or so. Is that possible? If it is, why haven't animals continued to expand the number of species up until the present day, or why did evolution stop at lions, 3,000 or so years ago, and not continue cat diversification?
4) There is no observational evidence from ancient literature for this explosive diversification.
5) Duff points out that scientific reasoning persuaded Answers in Genesis that there was not room in the Ark for all of the species we now have. The idea of rapid speciation after the flood is a new idea, not one that ancient Biblical scholars got from the text of Genesis. It has come about mostly, or entirely, because of the realization, by young-earth creationists, that it would have been impossible for Noah's family to house, feed, and clean up after 30,000 or so animal species within the dimensions of the Ark. In other words, young-earth creationists, who often accuse Christians of other persuasions about origins, that they are putting science ahead of a plain reading of the Bible, are in fact doing exactly that. See here.
6) This is a matter of culture and esthetics, I guess, rather than a logical objection, but what would Answers in Genesis have us do with all the Bible story picture books that show giraffes, zebras, lions, tigers and other animals, either with Adam and Eve in Eden, or on the Ark with Noah? Do they want us to replace these with pictures of their own inventions, the ancestors of the kinds? (Added June 8, 2022: The answer is "yes." see here for an AiG statement on this subject.)
7) Are we to believe that the names Adam gave to the animals would shortly be outdated, because of rapid evolutionary processes? (In most of the Old Testament, including Genesis, the names of people were chosen carefully, and matched the person's perceived character. Adam may have done that in naming the animals.)
8) Dogs have been artificially selected for thousands of years, but they are still dogs. Why, then, should we believe that natural selection would bring about an explosion of many species from an ancestral dog kind, in a few thousand years?
9) If hyperevolution was responsible for turning 137, 1500, or some other relatively small number of species (or kinds) into over 30,000 after the Ark landed, wouldn't it also have been responsible for rapid diversification before the Flood? If that had happened, wouldn't it have multiplied the kinds considerably?

Thanks for reading. For a chart showing many of the strengths and weaknesses of several views of origins held by Christians, see here. (All views of origins have weaknesses -- young-earth creationism isn't the only one that does!) For "What's wrong with young-earth creationism?" see here. For evidence that at least one of the important Bible scholars of the past, St. Augustine, did not necessarily believe that the earth is only a few thousand years old, see here.

Addendum, September 5, 2018: the Naturalis Historia blog discusses the idea that dinosaurs and humans lived at the same time, and points out several problems with that idea. 

October 26, 2018: I recently saw a post on the Bill Nye vs. Ken Ham debate, held in 2014, on the Gospel and Evolution blog. The reaction to the debate is of considerable interest, but this statement is especially pertinent to the subject of the post you are reading: "Ken Ham didn’t seem to have a problem at all with a 1,000 or so 'kinds' undergoing speciation since his alleged global flood 4,000 years ago to become the millions of species alive on the earth today, not to mention the billions that have lived and become extinct."

Thanks for reading.

Added November 30, 2018: A post by Naturalist Historia (R. Joel Duff's blog) discusses the adoption of evolutionary mechanisms in the explanations given by Answers in Genesis. 

Added December 31, 2018: David Heddle, of "He Lives" also writes about the problem that the large number of species raises for Mr. Ham and his followers. 

Added January 18, 2019: Naturalis Historia discusses horses, and related species, and examines what the Bible says about horses, and concludes that it's not possible for all horse types (including extinct ones) to have come from a single pair. 

Added March 5, 2019: R. Joel Duff has analyzed articles by adherents of Answers in Genesis, and, again, finds the hyper-evolution thesis to be spectacularly unbelievable. (In fact, Duff quotes one AiG author, who states that ordinary evolutionary processes could not have been responsible for the amazing number of bird species of the finch kind, if they all descended from one kind, after the Flood.) Here's one of Duff's articles. It has links to an AiG related publication.

July 18, 2019. This blog post was edited somewhat, including the addition of criticism 9.

August 20, 2019. See this post for more on the subject.

May 19, 2020. For more on proposed rapid speciation, from AiG and other Young-Earth Creationists, see here.

May 26, 2020. An article, published in Answers Research Journal, an organ of Answers in Genesis, and authored by important YEC scientists, says this: "In short, the YEC model proposes significant amounts of morphological change in a window of time that, by comparison with evolution, is extremely short."

July 18, 2022: Todd C. Wood, a young-earth creationist with solid science credentials, reacts to some who are calling Ken Ham, head of Answers in Genesis, an evolutionist. He is sometimes called that because of his belief in hyperevolution.