An abundant literature of hybridisation data is in existence, particularly for the birds and mammals. At least 1 in 10 bird species is known to hybridise. So for a world total of 9672 bird species, 895 species have bred in the wild with at least 1 other species. As well as interspecific, intergeneric and even intertribal crosses have been found. To these can be added a great number of hybrids obtained in captivity. Scherer and colleagues have seized the opportunity to harness this data by constructing cross-breeding matrices, and in some cases have added supplementary criteria. In this way, 14 Basic Types of animals and plants have been demarcated which display hybridisation within the Types, but not between the Types and their nearest taxa. The Basic Types include, for example, the Anatidae (ducks, geese and swans), Equidae (horses and zebras), Cercopithecidae (old-world monkeys), Canidae (dogs, wolves and foxes), Maloideae (apples and relatives), Aspleniaceae (spleenwort ferns) and Triticeae (wheat, barley, oats and rye). Further details are in the table at the end. An overview of the Anatidae relationships is shown in the diagram below.
Numbers under tribe names represent the number of species
(from Scherer, 1993)
Tadornini Tachyrini
/ 15 \ 3
/ / :\ \
/ / : \ \
Anserini - - -/- -:- - - - - Cairini
22 \ / : \ / 13
| \/ : \ / | Anseranatini
| / \ : /\ | 1
| / \ : / \ |
| / \:/ \ |
| / /:\ \ |
| / / : \ \ |
| / / : \ \ | Cereopsini
| / / : \ \ | 1
Mergini - - - -:- - - - Anatini
20 : 39
\ : /
\ : /
\ : / Stictonettini
Aythini 1
/ 16 \
/ \
/ \
Dendrocygnini Oxyurini Merganettini
9 8 1
During the European Creationist Congress in 1992, a number of
us had a brainstorming session to evaluate the known criteria
for demarcating the Genesis kinds and to search for the best way
forward. One potential problem is that there are hierarchies of
similarity, and it can be difficult to demarcate exactly where
the discontinuity between kinds may lie. For example, using the
morphology criterion, the sub-phylum vertebrata can be denoted,
but no one would argue that this is a single Basic Type: each
vertebrate class has its unique characteristics of form. But then
does one identify Basic Type with the class, or order, family,
genus, . . ? Scherer emphasised the objectivity of the hybridisation
criterion. Basic Types will only be possible among organisms sharing
similar embryological pathways, ie, having a common morphogenetic
machinery. He commented: `A Basic Type determined by hybridisation
will thus be open to empirical validation. If hybrids are known,
membership is unequivocal.'Scherer and colleagues have recently brought these ideas together into a publication, Typen des Lebens, which contains an overview, then a chapter focusing on each Basic Type. This is an important book. It may provide the most significant contribution yet offered in this decade to a creationist research programme.
| Phylum | Class | Order | Basic Type (BT) | Taxonomic level of BT |
|---|---|---|---|---|
| Bryophyta | Muscae | Funariales | Funariaceae | f |
| Pteridophyta | Filicatae | Aspidiales | Aspleniaceae | f |
| Spermatophyta | Dicotyledoneae | Rosales | Maloideae | s-f |
| Monocotyledeneae | Poales | Triticaceae | t | |
| Chordata | Aves | Anseriformes | Anatidae | f |
| Galliformes | Phasianidae | f | ||
| Falconiformes | Cathartidae | f | ||
| Falconidae | f | |||
| Passeriformes | Estrildidae | f | ||
| Carduelinae | s-f | |||
| Mammalia | Carnivora | Canidae | f | |
| Felicidae | f | |||
| Perissodactyla | Equidae | f | ||
| Primates | Cercopithecinae | s-f |
Sheena E.B. Tyler (1994)