[RadioAstronomer]

For example, why is the fossil record so lacking in examples of failed human evolution ?

http://www.talkorigins.org/faqs/homs/

Here are some added links:

Ardipithicus ramidus

http://www.msu.edu/~heslipst/contents/ANP440/ramidus.htm

Australopithecus anamensis
http://id-archserve.ucsb.edu/Anth3/Courseware/Hominids/04_A_anamensis.html

Australopithecus afarensis
http://id-archserve.ucsb.edu/Anth3/Courseware/Hominids/03_A_afarensis.html
http://www.msu.edu/~heslipst/contents/ANP440/afarensis.htm
http://www.mnsu.edu/emuseum/biology/humanevolution/afarensis.html

Australopithecus africanus
http://www.umanitoba.ca/faculties/arts/anthropology/courses/121/fyde/africanus.html
http://www.mnh.si.edu/anthro/humanorigins/ha/afri.html
http://www.msu.edu/~robin400/africanus.html

Australopithecus aethiopicus
http://www.mnh.si.edu/anthro/humanorigins/ha/aeth.html
http://www.as.ua.edu/ant/bindon/ant275/presentations/Human_evolution.PDF

Australopithecus boisei
http://faculty.vassar.edu/piketay/evolution/A_boisei.html
http://www.csus.edu/anth/physanth/an-img08.htm
http://www.sckans.edu/anthro/index.php?page_ID=305

Australopithecus robustus
http://www.mnh.si.edu/anthro/humanorigins/ha/rob.htm
http://www.mnsu.edu/emuseum/biology/humanevolution/robustus.html
http://www.oneonta.edu/academics/anthro/links/aust.html

Homo sp.
http://www.academie-sciences.fr/publications/comptes_rendus/pdf/CRPalevol_article4.pdf
http://www.amnh.org/exhibitions/atapuerca/gallery/africa.php?image=6&page=branches
http://www-personal.umich.edu/~jasonww/africa/transvaal2.html

Homo rudolfensis
http://www.mnh.si.edu/anthro/humanorigins/ha/rud.html
http://calvin.linfield.edu/~mrobert/originsfigure1a.html
http://www.msu.edu/~heslipst/contents/ANP440/rudolfensis.htm

Homo habilis
http://www.wsu.edu:8001/vwsu/gened/learn-modules/top_longfor/timeline/habilis/habilis-a.html
http://www.mnh.si.edu/anthro/humanorigins/ha/hab.html
http://dekalb.dc.peachnet.edu/~pgore/students/s97/bonetgar/habilis.htm

Homo ergaster
http://www.mnh.si.edu/anthro/humanorigins/ha/erg.html
http://www.msu.edu/~heslipst/contents/ANP440/ergaster.htm
http://cogweb.ucla.edu/ep/Ergaster_00.html

Homo erectus
http://www.wsu.edu:8001/vwsu/gened/learn-modules/top_longfor/timeline/erectus/erectus-a.html
http://www.mnh.si.edu/anthro/humanorigins/ha/erec.html
http://www.d.umn.edu/cla/faculty/troufs/anth1602/pchomoer.html

Homo heidelbergensis
http://www.mnh.si.edu/anthro/humanorigins/ha/heid.htm
http://www.msu.edu/~heslipst/contents/ANP440/heidelbergensis.htm
http://www.archaeology.org/9709/newsbriefs/dna.html

Homo neanderthalensis

http://www.msu.edu/~heslipst/contents/ANP440/neanderthalensis.htm
http://www.mnh.si.edu/anthro/humanorigins/ha/nead_sap_comp.html

Homo sapiens
http://www.mnh.si.edu/anthro/humanorigins/ha/sap.htm
http://anthro.palomar.edu/homo2/modern_humans.htm
http://hpgl.stanford.edu/publications/Science_2000_v290_p1155.pdf

[Victoria Delsoul]

I'll take a look as soon as I get some free time, thanks for the links, RA.

[PatrickHenry]

Gaps. All gaps.