Continuing the discussion from What science questions are important to you?:
Well, we do have several stepwise progressions showing the progression of organs. One often cited example is whales, and another is bird feathers/wings. Still, we will usually see gaps in the progression because the fossil record is not complete.
The case of the giraffe’s neck is interesting for a few reasons. See this article:
First, it is common to see arguments that the giraffe’s neck is irreducibly complex, and there could not have evolved.
Second, creationists also argue that the giraffe’s neck evolved by natural processes because it is the same “kind” as many other species without long necks.
Third, it is notable, also, that there is a quite bit more variation in species in the past, which makes a progression much easier to envision.
So this leads to some confusing messaging…
Even Ken Ham used this same language in 2005 about giraffes requiring irreducibly complex features to make a long neck but today identifies the long neck as the product of genetic rearrangements of DNA from an ancestor with a short neck.
Similarly, some YEC creationists wonder if walking whales were on the Ark, and think 4,000 years was enough time for whales all to evolve from non-aquatic mammals.
So, if YEC scientists believe that irreducibly complex structures can evolve, including the giraffe’s neck and whales from non-aquatic mammals, I’m not sure what the scientific difficulty is here.